Assuming you don't have a VLAN capable physical network, you could simply setup a second vSwitch without uplinks and add a virtual router (e.g. pfSense) which is connected to both networks and does the routing. With a VLAN capable network, configure the switch ports as 802.1Q (trunk/tagged) ports and set the VLAN ID's on the port groups.
Btw. why did you configure vmnet6 as standby?
André
