I have a Win 7 64 bit PC with a Win XP 32 bit VirtualBox VM. I'd like the Win 7 host to sit on one VLAN and the VM sit on another VLAN. The only thing I've found about VLAN tagging a VM is this post: https://forums.virtualbox.org/viewtopic.php?f=2&t=65345&p=314865&hilit=vlan+tag#p314865 in which the author uses a virtualized Ethernet adaptor supported by VirtualBox to force tagging on the interface. I've done that for my XP machine and I still cannot get it connected to the network.
I have the VM network adaptor in Bridged mode so it appears as it's own interface. Here's what I have for the port the PC is plugged into on my switch: