Group Memberships - Has anyone tried?

Hi all-

We are aware that a few of our donors split the cost of our membership levels with friends. I think those that do this are primarily seeking the benefits of better seating and earlier access to tickets, because the other benefits we offer aren't really able to be shared (these are party invites, dress rehearsal invites, etc...which are typically limited to two invites per membership). 

So, for example-

Bob is a member at our Patron level ($1500 annual gift). The membership is under Bob's name. But we find out that Bob actually splits the contribution amount for that membership with Jim (Jim just pays Bob his half). To us, Jim is just a regular ticket buyer, and he might not even have tickets under his account for the season because they are all under Bob's name. 

Has anyone tried or is anyone aware of a way to capitalize on this concept with some sort of official group membership, without causing immense confusion and losing out on money in the long run? Should we instead be focusing on ways to solicit the Jims of these scenarios so that they eventually see the benefit of paying for their own membership?

Just curious if anyone has gone there. Happy to elaborate if I need to.