Bone is bone and not very flexible. I tried to make a cow rib bow once, backed with sinew and it failed. That bone just would not bend. Now, there have been bone bows made and I read about them and used them for inspiration. Only to fail.
If I could find some bison rib bones, yeh, I try it again. This time maybe use a very thin osage core, bone on the belly and two or three layers of sinew on the back. Then do a sinew wrap.
It should work, if I can pull it back.