Any way to make symlinks or aliases resolve over a network with macOS?
So the answer is that both aliases and symlinks are both respected over network so long as the a share is mounted that contains the path to the original file in Finder i.e now has an eject button.
In my case I'd symlinked from an SSD to a HD, and while the SSD share folder was mounted, I had not yet browsed to any place on the HD so it was not mounted.