I like to add black tea to peach wines because it adds a little tannin bite and I think it balances & compliments the peach flavors well. I actually add in the tea loose leaf right into the primary. I add in up to 1tbs (about 3 tea bags) for peach wines made from concentrate or 100% juice. If using fresh peaches with skins then I back off on the tea down to 1 tsp per gallon.
Bananas could be added now just fine. Per the great Jack keller on his site here:
jack Keller's peach wines
You use about 1lb of bananas per gallon.