The Well of Wonders and Lake Nostos are entirely polar opposites (except for their regenerative powers in the water and that both locations' guardians come out of the water vertically). For example: one is a small well and the other is a vast lake. One guardian is ugly and the other is not. Nyx tried to warn the Cyrus, Taj, and Rafi when the Siren was seductive. What do you think their connection is to each other?
Yes I also remember that those waters were connected. I don't know excactly how though. But there's a well in Agrabah and a well in Wonderland, both of them were 'ruled' by Nyx. And there was some sort of a 'temple-thing' (that's how I call it) around those wells. That same thing was also in Victorian England where Alice lived in the final scene of OUAT in Wonderland, and there was also something like that in 3x12 where Philip and Aurora picknicked, although there wasn't a well in there. I think all those other wells are connected to eachother and to the well in Storybrooke and to Lake Nostos.