It used to be much easier to do this online. I did it three nights ago with a non-American SPG property by calling the reservation line with the other person in a conference call. She provided the information about her family so the reservation is in her name with my points. The hotel is expecting the correct guests which is important in this instance because the hotel will have to verify passports. I received an email from the hotel manager asking for some clarification. Without my having to ask, he has granted lounge access for them and put them on the UG list which is very, very nice.