I'm on several pubs, my impression is that at least the public ssb network is fairly well connected and it should not matter even if you ended up on different ones, I'd still see you.

It's a 3 hop gossip network, and pubs count as hops, so me -- mypub -- yourpub -- you works because 3 hops. Assuming our pubs are connected, and the pubs I can see are all interconnected.