HI Damessmer,
So you want to run multiple vlans in VMWare on BE6KS ?
This is what I did with my customer, If you want to run multiple vlans in vNICs, I used the trunk port from the switch config, BE6KS is using a Bridge Virtual Interface (BVI) which having G0/1 and Ge0/2 and members. So in the switch port which is connecting to BVI use a trunk port if you want to run multiple vlans, if the single vlan just use as access port.
I believe below guide will help you.
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/BE6000/InstallationGuide/11_0_1/CUCM_BK_C4BF1D12_00_cisco-be600…
Regds
Sasith