Hi there!
For what you've described, you're trying to accomplish a ESXi type configuration on Fusion... 
Anyway, I don't think that the network interface on Fusion is comparable to a vSwitch in ESXi, or has any do1q capabilities. I would compare Fusion Network (VMNET) more to a Hub.
But tagged traffic is like any other traffic (but tagged) and should pass to Mac Host through a bridge interface. So, my proposed would be to configure VLAN virtual interfaces on OSX side, and bridge them to the physical interface used by VMGuest configuration.
VMGuest (tagged) --> VMNet Bridge (tagged) --> OSX interface (tagged) --> OSX dot1q bridge (tagged)--> OSX VLAN virtual interface (untagged)
Another solution would be to use a second VMGuest, assign several interfaces (one for each VLAN plus one more for receiving tagged packets).
VMGuest (tagged) --> VMNet interface (tagged) --> (nic1=tagged) second VMGuest (nic2 = untagged) --> OSX interface
For creating more VMNet interfaces in Fusion 5 you must go to Settings->Network
For Fusion 4, it's a command line job. But you can find several references about howto on google.
I hope this helps...