The bison I see here in Pennsylvania (yes, farmers do raise them here) are for sure livestock. (They are a good lean meat) If they destroy your corn crop or other property, the guy who owns them should pay up for not keeping them fenced in. But you don't have the right to shoot them for trespassing on your land under any circumstances as far as I know.
I'm no expert, but I don't think there is anything much different between dealing with them and dealing with the average beef steer. They both can be nasty critters at times from what I know of them.