Originally Posted by xliioper

If on same reservation, they will also get your checked luggage, Sky Priority security/boarding, and preferred seating access. However, if you have more than one companion on same reservation, none of you will be eligible for comp C+ (or domestic FC upgrades) since that benefit is limited to one companion only. If you want C+ upgrade eligibility, you should book yourself and one companion on one reservation, and everyone else on a different one (or you can split them up after booking).