not sure it is totally out of the scope of the binding, but it can be. The ser2net side of it is for sure. That effectively exposes the serial port to a tcp port.
Then you have a couple choices. Within the binding you can support tcp connectivity, for example insteonplm does this. This can be done with a prefix within the config.
eg.
jeelink.port=/dev/ttySS0 ( or com x) for windows - this could be default direct to serial port
or
jeelink.port=tcp://192.168.x.x:7000 - this would be decoded to use tcp instead of the serial libs to get the input/output streams.
There is another option which would totally eliminate this type of coding within the binding, something like socat within the linux world, which actually does that connection to the tcp port on the server with the jeelink, and then the client side of socat which creates a virtual port on the server which has openhab. I have found this more difficult for things such as retry, etc.