not talking reciprocal rights. Just the number of SFS members are probably already counted.
Despite not being Tah members
They're counted in the crowd, but not as Waratahs members. Two completely different lists of members, no relationship at all. I get my information about games from the SCG Trust not the Waratahs because I'm not a Waratahs member, they don't know I exist.
EDIT: There are about 7,000 SCG/SFS Gold members, most of whom have a guest card and 2 club cards. This admits 4 people to Waratahs home matches. Obviously not everyone is a rugby fan, the 7,000 people includes league supporters and soccer supporters and those who go to multiple sports. Conceivably this would make 28,000 people who wouldn't bother buying a Waratah membership, when they already have free admission to matches. Of course it would be nowhere near that figure, but as a guestimate I'd say somewhere between 5-10,000 people are SCG/SFS Gold members who would otherwise buy or consider buying a Waratah membership, but don't.