Update: Support for SSH tunneling (port forwarding) has been added in Rebex File Server 2016 R1 - please check out the sample code. Please note that only outgoing tunnels are currently supported.
No, tunneling (port forwarding) in either direction is not supported yet. However, several clients already asked for this feature, and it's very likely we will add it in the next release. If you would like to try a beta when it's ready, please let us know. Thanks for your suggestion.