Are you talking about the back of the bow in bowyer's terms ie back vs belly. Or non bowyer talk ie front vs back(rear)?
The top picture looks like its showing the inner split of the stave, not what is commonly used for a bow's back.
If this is correct, those wrinkles were in the wood before steaming, because that side would be under tension, not compression during the recurving process. You can sometimes get wrinkles during steam bending but that happens on the inside surface, with an unsuitable timber species, or very tight radius bend. Your tips are more flipped than tightly recurved so I doubt this this is an issue with your stave.
So if the wrinkles were in the stave originally, then they shouldn't pose much if any problem. That being said any bit of character or figure in bowwood is not going to be as strong as clear, straight wood. The tips even if you intend them to bend when drawn should still be relatively stiffer than than the rest of the limb, and therefore not under extreme compressive force.
