According to the VMware Workstation 6.5 User’s Manual, WS65 "supports for 10 virtual E
thernet sw
itches on
Microsoft
Windows ho
st operati
ng
systems. So basically, you can do that."
As per your requirement of two virtual subnets, you need to create two Team LAN Segments accordingly. As soon as you have created a VM with at least one virtual NIC, assign the NIC to the corresponding LAN segment, you then have a VM working in that VLAN or subnet. The same for the second VLAN or subnet.
For detailed instructions and steps to create team LAN segment, VM and virtual adapter, please read from P260 of the user's manual.
FYI
VMware Workstation 6.5 User’s Manual
http://www.vmware.com/pdf/ws65_manual.pdf