I find most SPG properties do extend benefits to elite members regardless of their name being on the rez or not. Every time I've chosen to share a room with a lower/non-member that has already booked a room, just showing my card at check-in has resulted in on-property benefits (lounge access, internet, and even sometimes room upgrades). However, since my SPG # was not on the rez, no points to me and no Plat points to friend.

Of course there will be some FDCs that do not know the rules and what is and is not allowed and therefore will act differently, so I go in expected nothing and being pleased when a bone is thrown my way.