what to do with tea after soaking raisins

Make a rice pudding? Or use it as as part of a marinade. I imagine it would be tasty with chicken or pork. There are also various recipes to make cakes using tea as the liquid component. King Arthur did a bit about using tea to bake with, for one place to start.

Soaked raisins are supposed to help with arthritis... I'd drink the raisin tea!

Taste it. If you like, add to hot tea, iced tea or a smoothie.