tea also has caffeine, although in smaller quantities. Maybe you mean that you don't care so you go by taste, just specifying because there's a common misconception about tea not having caffeine.
are you saying chamomile isn't called tea but it's one of the teas without caffeine? if so that's very confused.
camelia sinensis is tea. when i said that other things are casually called tea, i mean that what chamomile tea, for example, ought to be called is a tisane or an herbal infusion. casually, people might call it a tea; some people are so casual about it that they think it actually is tea. but it isn't.