The Hyde Park Juggling Meets still happen every Tuesday around 7pm onwards. I haven't actually been there myself (yet) but I have a friend who does some contact staff-ing and he goes on a regular basis

The UWA Juggling Club also has occasion fire spinning events and has a weekly practice session every Friday.
Apart from that, I'd say the best way to meet other spinners would just be to do some spinning in a public place (not necessarily with fire mind you) and hope someone notices you. I was doing some fire poi the other night and a jogger ran over and as it turns out he'd been practicing poi for a few years

Hope this helps
