Wayne,
In the past it seems there was always a good reason to add an official Royal prefix to a golf club. Take Colwood for example. I understand someone from the Royal family (can't recall who) frequented the club for many years, during trips to Canada. That person liked Colwood enough to designated it an official Royal club.
Royal Mayfair?! I don't get it, but hope there's a reason that makes sense of the recent Royal designation there.
Funny, my home club, Essex, in Windsor, Ontario's 100th anniversary took place in 2002. Someone at the club suggested the club request a Royal Essex desgination. That was met with a logical, "why?" There's absolutely no reason for Essex Golf and Country Club to be designated Royal. Again, Colwood's makes sense.