I'm a Plat who got a ticket for my wife to join me on my most recent trip.

I was Group 1 and she was group 4. We boarded together at all 4 legs - BDL - ORD DEN - ORD. no questions asked.

By the way - it was great to have my wife with me for the 2-1/2 hour delay in DEN and then a 3 hour delay in ORD. She got to truly appreciate the "glamour of travel".