You are mixing together the two approaches described in the topic I’ve referred to.
You can either use one /interface vlan vlan-id=x on each ethernet interface and bridge these /interface vlan together in one bridge per VID, or use a single bridge for several VLANs, and only in this case it makes sense to use the rules under /interface bridge vlan.
Have a look at these two pictures to see the difference between the approaches.