According to the experience i have had this is the case in CBA. Even the branch staff gets commission if they cross sell you credit cards, home insurance etc. I think one of them told they get something like A$50 etc.
I will have to admit that i have no first hand experience or proof of all this but i have been definitely told of this by CBA guys itself...
In one of the instance when i threatened to move away from CBA if they didnt increase the discount from .88% to .9% the person on the phone told me that she would do her best to get me the discount as only then she gets paid as well and obviously i got the discount. I don't remember which department she belonged to but i had dialled their home loan number and it got routed to her from there. Never met her face to face.
Mortgage Innovation group is definitely on commision fully. They get no base salary....