I am just a guilty of trying to pull this off.

Last year my wife and I got married and Westin was the hotel of choice for our guests as we were also having an event at the hotel as well.

I asked if it were possible to get the points for the guest that were staying at the hotel that were not SPG members. What I was told is that I would get the points for the "meeting" event (I forget how many they were) and that the only way I could get the points for our guests was to book the rooms in my name and prepay for the room. Otherwise their was no way that they could credit my account the points for what someone esle was paying for.

Honestly I would be surprised to see how they were able to pull this off as I explored every possible option to rack up points from non SPG that would attend out wedding??