I asked the help desk and received this reply....
Thank you for your message. I do not have a current count on how many
Country Clubs exist at this time on WGT, but it is quite a lot.
I then asked again
Surely there must be a way of estimating the number of clubs as
well as players...!!
I am trying to settle an argument within the club over the point
of playing country club clashes and the fact that our club came 89th in the
last clash. Now that is good going if there are 10,000 clubs but not so
exciting if there are only 500....
and received this reply
Unfortunately, there is no way to tell exactly how many Country
Clubs have been created on WGT as there is no statistic tracking them as anyone
can create one with 50 Credits. We apologize for any inconvenience, however I
can assure you that 500 is an extremely low number.