Another forum member has created a topic three weeks ago to discuss about the bonus changes of Stake and BC.game. Probably these established casinos are reducing the bonuses to maximise their profit. But reducing the affiliate commission rate without any prior notice is a bad move from the casino team.
I play at BC, I am not an affiliate but I play for one, under Gosu! If they really did this (and I hope there is an explanation for this case), I will simply stop playing there. 
'efialtis' won't take it easily if BC.Game has really decreased the affiliate commission rate from 35% to 9.8%. BC.Game is at the top of GOSU review, it will highly effect on their ratings if they have made such unpleasant changes. A forum member has made a long dissatisfactory post in BC.Game ANN thread yesterday (it was a copy paste from Trustpilot review).