I am planning on booking domestic award travel for me and a companion traveling together, using my miles for my ticket and my companion's miles for that ticket. If I book online, I believe that I will receive two separate PNRs. I assume that if I book through the telephone, I can have both tickets placed on a common PNR.

Is there any benefit/disadvantage to having a common PNR, and is it worth the fees for booking by telephone?