The picture says it all with a description which is very important. My biggest concern is that I don't want clients on Router1 or Router2 seeing one another. I have used MT for 6 years but no experience with VLAN's. We usually just use Mangle or routing marks but it's time to test out VLANS.
I will modify the diagram as needed if requested and answer all questions quickly.

Basic steps:

Place a VLAN 1001 interface on the Ether interface on the NanoStation. Use that VLAN interface for all data configuration such as IP/DHCP client, bridging to WLAN etc.
Add Ether 5 to the existing bridge on Router 2 and connect to Ether 5 on Router 1.
Place a VLAN 1001 interface on Ether 5 on Router 1.
Add the VLAN 1001 interface to the bridge on Router 1.

Since you haven't placed an IP on Ether 5 on Router 1 that subnet will not impact Router 1 but there are certainly further steps that can be taken to secure the system.

Thanks a bunch. I had did everything you spoke of with one exception. I attached the VLAN directly to the bridge on Router1, instead of adding it to ether5 and then adding the VLAN to the bridge as a port.
Thank you very much. Perfect solution.

Thanks a bunch. I had did everything you spoke of with one exception. I attached the VLAN directly to the bridge on Router1, instead of adding it to ether5 and then adding the VLAN to the bridge as a port.
Thank you very much. Perfect solution.

Be careful that you haven't joined the untagged LANs together..... !