Re: "Cannot add 'match vlan 2' to a map applied to a non VLAN interface."
Thanks for posting your question on the forum! I moved your question to the NetVanta 3100 discussion space so that other users looking for help could view it as well.
What you are trying to do is valid, but since ethernet 0/1 is a layer 3 IP interface, it is unable to match by VLAN. The best way to accomplish this is to create an inbound QoS map and apply it to VLAN 2. In this QoS map you would tag the VLAN 2 traffic with a DSCP value. Then you would match that DSCP value on the QoS map you have assigned to your WAN interface.
You can find a similar example in this guide: Configuring QoS in AOS Specifically, you will want to look at example #4.