look here for non-resident wild bison hunting.
http://gf.state.wy.us/
the hunts in my area are conducted on the national elk refuge and grand teton park. thoroughly regulated and supervised. don't know the odds of drawing a tag but success rate is high. generally quite open ground or riverine habitat.
might be info about public land hunts in the rest of the state.
there are several options for private land/herd hunts in eastern wyoming but my knowledge is limited to what i see on the internet.
not sure if open to non-resident, but i've heard about wood bison hunting in canada as well.
good luck