Still trying to figure it out myself but that vlan part of wireless interfaces is moved elsewhere as of ROS7 (only with wifiwave2 ?)
Use the bridge.
https://wiki.mikrotik.com/wiki/Manual:Interface/Bridge#Bridge_VLAN_Filtering
I would be grateful for a “simple translation” ROS6 to ROS7 for this particular aspect. I’m sure the more savvy members can come up with something like this.
One could also look at this thread but to my liking, this is overly complex (I even tried to copy -paste such a config to a spare hAP AC2 for testing, didn’t work at all !)
http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1