I haven't used bamboo on a bow yet, but I do make bamboo flyrods as part of my business. Keep in mind, all of my experience has been with Tonkin bamboo. I have read where bowyers use some other species, i.e. Moso, and I'm not sure how these would react vs. Tonkin.
In rodmaking, we basically use 3 different methods of heat-treating the bamboo. In the first, an oven is used, taking the bamboo to 350* for 10-15 minutes. You'll have to experiment with the oven, but a heat gun powered tubular is the cheapest to make. In the second method, referred to as "flaming", a propane torch is passed over the enamel, or outer, side od the bamboo. Try to keep the flame moving slowly, and pay attention to the enamel crisping. The color you want to shoot for is generally 2 shades darker than you want to end up with. You'll lightly sand with 220-300 grit before putting a finish on. In the third method, the outer color of the bamboo is not changed, but the bamboo is still tempered. In this method, you again use a propane torch, but you flame the inner pith side. Since the pith is very soft and porous, it will immediately flame up and then go to a "coal" look. Here's a link on what you want to happen
http://www.rodbuildingforum.com/index.php?showtopic=13648 This shows the outer nodal surfaces sanded down for rodmaking, but you can prep the nodes however you want.
All three of these methods will temper the bamboo and speed up it's action, plus remove moisture. The faster you finish backing the bow and get a finish on the bamboo, so it can't re-absorb moisture, the quicker the bamboo stays.
Hope this made sense to ya, feel free to PM me if you have any questions,
Canerod