The pass I have (from last year) reads...
Present this complimentary WorldClubs visit card at any WorldClub or affiliated lounge worldwide to aquaint yourself with its many comforts and amenities, compliments of Northwest Airlines. This card is valid for one complimentary visit and must be surrendered at time of admittance.

I would read "yourself" as a single person and not including your family. The passes I've gotten from UA and CO specifically state one person...