I play Guile and I recently played with RenoMD, an extremely good bison and I had no clue what to do against his Bison pressure and I can’t find anything about the matchup with Guile. Help? And I apologize if this is already somewhere, and I just cant find it.
Lots of things.
initial headstomp, block, jump back fierce or roundhouse, flashkick, if you are standing when he leaves the ground you can crouch and it will whiff over you.
for the followup
block, cr fierce, jump back fierce, jump forward fierce, jump back roundhouse, flashkick if the headstomp hit you, don’t lose your croch charge, if he tries to hit you you can just flash kick him.
The key is to stay in the position where bison can’t headstomp without being hit or he is too far away and you can counter it easily
And don’t forget about the Guile thread. 
Plenty of help for Guile there. By the way, I prefer to jump back and air-throw him before he stomps me. Otherwise, if you end up blocking it, you’re at the mercy of Dictator’s mix-up. The options listed above will help, though.
Well if you block a stomp it is not hard to hit him back if he tries the punch follow-up.
My worry if you were guile is that bison is now in the range where he can stand roundhouse your sonic booms, which sucks hahah