This is complicated. I would say:
1. Only for members to see: this lowers the chance that a con-artist passer-by might decide to drop in on a meeting for a little trickery. It also decreases the chances of other sabotage.
2. I would say make it 100% public: we have a member here in the NW that joined after seeing that there were local meetings. It is a good way to get people interested in the site and in photography because it advertises the fact that they are near a local band of shooters with which they can share their enjoyment of the craft. This is a big thing for me, at least. Not to mention, we would want to pull people in, not shut them out. If someone is surfing the net looking for fellow RFers, and they come across the RFF - which they WILL - we would want them to find the thread for the local meeting, want them to come in and say hello and to find the real physical community aspect immediately. Once they get a sense for their local RFF group, they are more likely to find themselves connected here, more likely to become part of the community instead of just another username from the infinitely vast internet.