I read on a bamboo site about bending boo. Most is done while the stuff is reasonably wet. It was suggested to boil dry boo. For what you want, I cannot see how steaming will hurt, but I can see how a dry heat could cause a burn or the use of oil, a typical dry heat supplement, would cause problems for lamination.
Then again, if you are going for something like a Perry Reflex, I dont think you even want to preset the bend. I think you would want to retain its ability to bounce back.