You are missing the bridge itself (i.e. the intrinsic bridge-to-CPU port) as a tagged member for the new VLANs, without these there is no connection between the /interface bridge vlan IDs on trunk/access ports and the /interface vlan connected to the bridge. So in this case:
/interface bridge vlan
add bridge=bridge tagged=bridge untagged=ether4 vlan-ids=10
add bridge=bridge tagged=bridge vlan-ids=100
See http://forum.mikrotik.com/t/routeros-bridge-mysteries-explained/147832/1 for more information. There is nothing actually wrong with using untagged and tagged VLANs on the bridge-to-CPU port, some people just prefer them to be all tagged.