Hefe's are generally fully conditioned and peak about FOUR weeks after brew day, so they have conditioned plenty. That sweetness you taste is probably the banana phenols that are contributed by the yeast during fermentation, and not malt sweetness, so it is supposed to be there, and desireable in a Hefe.
Anyway, point being, the Hefe was likely ready to drink a week ago. Throw it in the fridge!!