I have traveled with family on the same flight but we were 10 people with 4 different PNRs due to diverging itineraries after our holiday. In NBO staff allowed me to check bags on behalf of others due to increased gold allowance but it had be tagged as my bag, so we couldn't effectively 'pool' our allowance. Same thing happened in DXB when we wanted to check in an extra bag after a long stopover; it had to assigned to an individual who still had allowance. Not sure if it would be different if we were all on one PNR.