Hello Fabian,
Yes, as far as we know, you can access a CueCore using the vManager over a VPN connection. However, as far as I know you don't need to know the protocol and the port number for building a tunnel. If the tunnel is build, the two sub-networks will act like there are combined and thus the vManager would just find the CueCore. I don't think there are any prerequisites for the connection between the CueCore and the vManager since this uses UDP and no special port (16945), so nothing special there.
I hope this answers your question.
Best regards,
Jurrien