Using comp/env only works when the packages are in the same .ear (if then;-), and when you have explicitly mapped the comp/env location your program uses to the actual jndi location. Try looking up the cf under what you see it bound under in jndiview (probably java:/eis/myConnector). You are running the servlet container in the same vm as jboss, right?
To use jndiview, go to port 8082 or 8080/jmx-console with your browser and find the jndiview mbean under jboss. On its detail page, press the list button.
Using comp/env does in fact work. My problem was that
I hadn't added a <resource-ref> to jboss-web.xml.
Once I did that the lookup succeeded, and the connector
is now responding to the servlet.