Per Marriott's T&Cs you would get points for both rooms but you will only get night credit for one room (i.e. 2 nights).

With that said, my experience is that "mistakes" seem to happen much more often in non-FS Marriotts where I would get 4 nights credit. FS Marriott's seem to not make that mistake very often. But don't count on a "mistake" happening. If it does, then you got lucky. If it doesn't, you got what the rules said you should get.