Read the first link once, twice, 3 times … try to adapt your config.
Read again (because you WILL have missed some parts).
Second link explains you what a bridge really is in MT context.
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1
http://forum.mikrotik.com/t/routeros-bridge-mysteries-explained/147832/1