Hmm, not sure if a vapor barrier is needed. Make sure to look at the
manufacurer's recommendations. Wood directly on concrete is generally
not good.

Definitely use a vapor barrier. I've seen enough moisture in even 30
yr old slabs to damage wood flooring. Most people use 6-8 mil
polyethylene sheeting, taped with seams sealed, then float the bamboo
flooring over that. Some old-timers swear by glueing heavy weight tar
paper to the concrete, then gluing the floor to the tar paper.

Regards
-Greg Pasquariello
Fair Pacific Bamboo
www.fairpacific.com