No, but I've done some simple hand calcs, and from what I can tell the downtube carries the lion's share of torsion, which is why modern frames tend to have massive oversized downtubes. Under just the weight of the rider without any force on the pedals the entire frame acts like a truss with all the members in either tension or compression. Torsion and out-of-plane bending are introduced when power is applied at the pedals due to the Q-factor. IMO, the downtube and chainstays would better remain as steel, but the rest could still be made with bamboo. Of course, if the seatube is bamboo, this could be a problem with seatpost fitup.