Unfortunately you are kind of screwed. V-Station on Logic can only import banks that are in Midi format ( .mid files ) as it is unable to read and convert .fxb files. I think it can read .syx files as well but I have never tried this.
This is done using the import button in the memory section of the Globals screen.
I just tried this with a .mid file and it works on the latest version of V-Station
In theory if you still have a copy of Cubase lying around you could export your banks as .mid files and then import them.
The kicker is that no preset names are loaded which makes this process pretty useless
Novation appear to have abandoned any further development of the software with just a few maintenance releases in the past years.
Sorry not to be of much help. I pretty much gave up on V-Station a few years back