I have my device configured as a AP Bridge, and a virtual Station pseudobridge.
This works as long as the main device have the correct channel/bandwidth as the AP that you are trying to connect to with the Station.
The reason why I have the main device as the AP is that if I’m in an area where there are no known network to connect to, it will still create a AP to connect to. Where as having the main device configured as a Station it would have to connect to AP before it sets up the virtual AP. At least this is my experience.
I have a script that scans for networks and configures the main to connect to that network here: http://forum.mikrotik.com/t/script-to-run-ap-bridge-on-main-wlan-interface-station-pseudobridge-on-virtual/100687/1