Bamboo's are VERY passive sharks. Some people like to consider them as excessively aggressive, to feed their own ego of owning a "shark." The truth is, they are not very aggressive at all, and in no way fit the stereotypical view of a sharks personality. These sharks tend to "not" show aggressiveness towards other sharks/fish. Typically, they will only hunt down/prey on fish/creatures which they know are food, or are sick/injured.
Their jaws are designed to crush/grasp. Not cut/slice. It would be very improbable that one would exert the energy required to hold onto another perfectly healthy sharks fin/skin long enough to do any damage.
Fight over food? Yes, of course. Until one takes the food from the other. Kill each other over it? Nope.
IMHO, your sharks will be fine together as long as you are cautious while feeding. Don't create a situation where they MUST compete over food.