If money's your main priority though (and who could blame you?
With two women there are lots of feelings involved and maybe even a little drama, even from the get-go.
So do you feel like being a greedy lesbian today and dating the upper echelon of your demographic?
Even the most feminine of lesbians (and you'll find that the very wealthiest among lesbians tend to be among the most feminine; in appearance at least) have a need and appreciation for the strength and masculinity that other lesbians bring to the table (as opposed to many of their heterosexual counterparts).
The more friends you have, the better chance that someone among your friends knows of a wealthy woman who shares your orientation.
Other lesbians and rich people of all varieties are the best types of people to know (though it's certainly good to have friends from all circles; these are the two that are going to be the most likely to be able to point you to what you're looking for) for your situation.
Generally what you're looking for in these types of atmospheres is the more refined and feminine looking girls drinking only the finest alcohol (champagne is a good thing to look for).
Think “lipstick lesbians” as opposed to “flannel shirt” lesbians.