Same problem. I did buy the game 3 days ago together with VIP.
And it´s the same as it was in Forza 5: It does not work.
I get no VIP bonus in the wheelspins and the cars are not free.
Funny part is, the game tells my, that I already did buy the VIP cars which I did not do.
Any help?
All the fixes with resetting and installing it new do not work (still have the same problem in Forza 5).