Word has it that AMERICAN Hefe yeast is essentially a Kolsch yeast, and you wouldn't have had any bananana nor clove even if you pitched correctly. I've used WhiteLabs American Hefe yeast, and the beers turn out like Widmer or Pyramid.
You can ferment both cool and you'll still have 2 nice beers. Nothing wrong with dry hopping as planned. You may actually find it to be a happy accident.