I have definitely considered doing a metheglin with something from Teavana...I don't routinely add tannins to my mead except in certain circumstances, but it can be a valuable addition at times. I would think that many of the Teavana teas would have less tannins than your run-of-the-mill black tea (many of the Teavana teas I've tried use white or green tea as the base...)
Packaged: Fruitcake Old Ale
Primary: 15 Min Pale Ale (Waimea hops), Unoriginal clone (hoppy session mead)
Secondary: Why do I keep this line here...?
Bulk Aging: Simple Cyser '15, Cocobochet, Wild Cider (2014 & 2015)
Planned: So many ideas, not enough time to brew them....