Dear OP. I think you have almost all possible combinations (routing rules, routing marks, bridges, VLAN). All configurations (both posts) can work.
(On the VLAN: study the complex theory in Mikrotik as @anav mentioned (documents the bridge method). Normally you bring all involved ethernet interfaces to the same bridge, if you use the “bridge method”, the other way of doing it is the “switch method”. Methods cannot be mixed). VLAN’s can be of benefit in the WAN (upstream) and LAN (downstream) hybrid connections, where you separate the VLANs later, in a Switch, Router, Server or AP.)
Do you think I can still do this (associate the vlan with certain pppoe) without connection marks and routes based on marks
You have the link to this: http://forum.mikrotik.com/t/routing-based-on-source-ip-or-source-interface/111479/1