Hard to go wrong with fire enchant and anything. Your combo would be excellent for vampire hunting, to counteract their drain health spells. Fire and Frost would be a great dragon hunting bow. Fire and drain stamina would be good for all-round use. If you have put any perks in destruction skill tree (fire spells) would be the icing on the cake.
I have never got that far on the enchanting tree but am working on that as we speak. Can't wait till I make my first dual-enchantment bow.