Bamboo is a very hard and light material. It does not resist impact at all, and even some hard swings with a dry bamboo bo with no impact, can result in cracking, splintering, etc. This isn't too much of a problem for shorter weapons, but for a bo, that's too much bending for bamboo.
I like to think of it as more of a substitute for metal, rather than wood. It's great as a laminate material for composites, but not as a stand-alone weapon.
If, on the other hand, you're going to make some display weapons, out of bamboo, then that's fine. You can get some really beautiful looking weapons with bamboo. I would strongly recommend treating them with wood preservatives, followed by a couple coatings of polymerized tung oil. This will give you a hard, smooth coat, and really bring out a nice shine with the bamboo.