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.