RB2011UiAS-2HnD-IN setup with Sector Antenna

Hi every one
i read a number of topic about Vlan and the great Feature of Switch chip that include with RB2011 but i can’t understand how Vlan work if the port become a switch port
i want to use the Switch chip in my network with Vlan to prevent loopback & make (PPPoE) to my service provider through ether1 (Wan Link) and use that connection to provide Internet to my home router + NTP service to my sectors (RB912) and RB2011 without pass net to sector (just NTP to correct the time in log) but to pass throw the PPPoE for my clients (which want net from my service provider throw PPPoE connection)

this pic show what i want to do
problem.jpg