Bison are not a shailoh as they had them in Europe and we ate them. The problem is they are hard to domesticate, whereas Aurochs were tamed into our type of easy to raise cattle.
Turkeys were more of an issue but the tame domestic turkeys are so similar to chickens that they decided to treat them similarly, though the wild ones were usually regarded as dubious.
I question the wisdom of asserting that two critters that can breed are of different species just because they look different. If you hold that way you would conclude the humans include multiple different species (well some people held that way, but the Allies hung a lot of them 70 years ago). Also, we have mesorah that humans are all one species, which suggests that physical appearance isn’t a factor in deciding what a species is. Bison and Cattle produce fertile offspring, whereas horses and donkeys don’t (which has halachic signficance).