WebLogic provides a proxy JDBC connection. So a remote client can get a connection to a datasource via the WebLogic proxy. I can't see the performance advantage as the client then has to pass it's statements and data over the wire to the application server which then executes the actual SQL to the datasource fetches any data pending and forwards that onto the remote client.
JBoss does not provide a proxy connection. It provides a real JDBC connection and that means that only a client operating in the same JVM as the connection pool can use the connection. The physical handle to the connection is in the JVM so the reference is meaningless outside the VM.
The JBoss datasource name binding is such that remote clients cannot locate the datasource name.