Yes, other stuff can be added to tea. Good tea does not need any extra help from flavourings, and the stuff that you buy in bottles out of a vending machine is about as much tea as my elbow is. Avoid it.
I am not the biggest fan of flavoured teas outside of genmaicha and Lapsang Souchong, but here are the more popular ones.
Jasmine tea: Hugely popular in northern China, this is tea flavoured with jasmine flowers. A lot of artistry goes into making good jasmine tea, so if you find a good one you’re in for a treat.
Earl Grey: A blend of black teas flavoured with the oil of the bergamont orange. I imagine you’ve had this tea before, probably in a tea bag. “Real” Earl Grey has actual bergamont orange bits in it. This is my mother’s favourite tea, and I used to really like it, too, but I’ve moved on. It’s still not a bad tea, though.
Morroccan mint tea: The Moroccans have a unique tea culture. They use only gunpowder-style green tea, boiling it for a good fifteen minutes or so until it becomes very bitter and strong, adding in mint leaves. They pour it from a height so that a foam forms on the top of the glass, and since the tea is so bitter it is taken with quite a lot of sugar.
That’s about all I can think of, honestly, that is worth telling you about. Other people can help you more here. My biggest and best advice for flavoured teas is to never buy anything with “natural flavour” on the label. This means “sprayed with extracts”, and extracts taste very simple and vanish very quickly. Get the real deal.
Sometimes you will see “herbal teas” called “tisanes” or “herbal infusions” or variations thereof. This is mostly due to the fact that tea purists would like to have it so that only preparations involving the use of the Camellia sinensis plant would be called “tea”. I tend to agree with this idea, though I sort of go between “tisane” and “herbal tea” depending on who I’m talking to. “Herbal tea” is also sort of inaccurate because oftentimes the infusion in question doesn’t contain any “herbs” at all, but flowers or roots or fruits. I say just stick with tisane, but I won’t tear your head off if you use “herbal tea”. It’s really not that big of a deal.
Anyways, tisanes go back waayyyyyy farther into history than tea does. For as long as humans have been boiling water, we’ve been throwing plants into it to make the water into something else, be it a magic potion, a medicine, or just something tasty to sip on by the campfire.
There are way, way, way too many tisanes for me to list. Korea alone has probably over 200 different kinds. I’ll just talk about the most popular ones. As a note to remember, most tisanes should be brewed with freshly boiled water. Tisanes are also usually cheaper than teas…usually. Good tisanes can be had for much less money than good tea.
Chamomile: A member of the daisy family, chamomile is a big component in the ever-popular “Sleeptime tea” tea bags sold by Celestial Seasonings. I probably don’t need to tell you that real chamomile, made from the whole dried flower heads rather than chopped up bits in a bag, is much tastier. I find it very sweet, with a honey flavour. Whether or not it actually helps you sleep is up for debate, but it’s pretty relaxing and caffeine free. I’m drinking some out of my infuser mug with cats on it as we speak. Good chamomile can be obtained from Upton Tea Imports.
Rosehip: Made from the dried fruit of the rose plant we all spend so much money on come Valentine’s Day. Rosehips themselves are tasty and chock full of vitamin C, but how much of that makes it into the tisane you make from them is pretty variable. Rosehip tea is pretty tart and sweet, like rhubarb pie, and I find it just as relaxing as chamomile. Again, Upton Tea Imports sells pretty good rosehip tea.
Catnip: Yes, the same catnip that makes your cat go insane. Usually used as a sedative, though like chamomile the scientific data doesn’t really show much of a sedative effect. It won’t hurt you, though.
Chrysanthemum: Quite popular in China, usually using whole flowers. I can’t remember if I’ve had any, but since the Chinese have been drinking it for about a 1000 years, it’s probably pretty good.
Ginger: One of my favourites, made from ginger roots. Quite peppy, without the caffeine buzz.
Citrus: Lots of tisane mixes include orange peel, lemon peel, etc. Adds a great zing.
Rooibos: Sometimes called “red tea”, it comes from a bush that grows in South Africa. It’s quite popular, often with other flavourings. I think it tastes vile, myself, but don’t let that stop you. No caffeine, either.
Lemon grass: Sometimes added to mint tea, or used on its own.
Barley tea: Popular in Japan and Korea. Drunk chilled in summer.
Yerba Mate: This South American plant is becoming quite popular. It contains caffeine and is traditionally brewed in a calabash gourd and sipped through a metal straw that filters out the chopped up mate bits.
Pennyroyal: I include this here as a warning. If you are PREGNANT, DO NOT DRINK PENNYROYAL TEA. It contains chemicals that induce abortion. I’d say everybody just avoid it, but especially pregnant women.
St. John’s Wort: Used as an anti-depressant, though it most likely doesn’t work. Do NOT drink it if you are taking anti-depressants as it can interfere with their action.
There are so, so many more, including a whole galaxy of mixes of different herbs, flowers, fruits, roots, and nuts. There’s really no buying advice I can give you besides avoiding products with “natural flavours” on the label. This means they have been sprayed with extracts, and extracts do not taste good and vanish within seconds of brewing. Stick with natural and you’ll be getting the right bang for your buck.