Of course, you would need to run the 3002 in Network Extension Mode. While I have not tried running DLSw+ over a VPN link yet, I can't think of any reason why it wouldn't work.
What type of access link are you planning on using on both ends? If you are looking for something like an ADSL connection, you may want to be careful with timeouts/keepalives on the link so that the tunnel does not terminate from under the DLSw+ connection.