Yep...as long as they're not replacing a milk feed with it, and there's no sugar or honey added, I don't think it's that bad an idea at all. but, as others have said, only if unsettled.
My sister lived in germany for a whiole, and i remember her giving her DDs chamomile and fennel tea......i think they were from a tub of granules (i was v young as well at the time).