Cannabinoids are not solvable in water, so the buds (decarbed or not) in water for tea would get chlorophyll and stuff.
I'm drinking tea right now because I have a tooth ache today.
I added a canna tincture to my peach tea... and that"s the same way I would make a recreational tea.
Unless you like milk in your tea...I don't. But you can make canna milk and add it to tea.
There are a couple things online about powered cannabis
http://herb.co/2016/01/21/will-powdered-cannabis-next-big-thing/
and another on making THC water solvable
http://blog.sonomechanics.com/blog/water-soluble-cbd