Configure port on router as trunk with all VLANs needed … here’s how to do VLANs in ROS: http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1 … Tutorial may be geared towards switch-like configs, but is usable also for routers (even router-on-a-stick variety).
And a suggestion: upgrade your router to latest stable, which is 7.16.2 ATM.