What exactly are you trying to achieve with VPLS?
I have the Hotspot interface in a VLAN on the bridge on the core / BNG router with the bridge on the remote CAPs (with CAPsMAn local forwarding) tunneled over VPLS to the hotspot interface bridge on the core / BNG router.
You may find these two MUM presentations I just found onine useful:
Using BGP may introduce additional unnecessary complexity for you, particulalry if your network is small.