The Cartel ID is a VM's Leader World ID (LWID), no matter how many world ID's are associated with the VM.
Let me try to explain this with a quote from VMware KB: Mapping a virtual machine world number to a virtual machine name and a short example.
... Each virtual machine is comprised of several worlds. ...
I created a 2 vCPU VM "MyVirtualMachine", powered it on and ran the following command to get the CPU 0 world ID as well as the cartel ID. After this I took a look at the VM's vmware.log file to find out which world IDs were created for each of the 2 vCPUs.
~ # esxcli vm process list
MyVirtualMachine
World ID: 4238
Process ID: 0
VMX Cartel ID: 4237
UUID: 56 4d 1f e3 13 71 a8 99-57 e8 56 20 86 59 89 75
Display Name: MyVirtualMachine
Config File: /vmfs/volumes/4feba845-ccf83f21-cd12-000c2976faee/MyVirtualMachine/MyVirtualMachine.vmx
From the vmware.log:
2014-07-13T19:59:21.854Z| vmx| I120: Log for VMware ESX pid=4237 version=5.1.0 build=build-732143 option=Release
2014-07-13T19:59:22.064Z| vcpu-0| I120: VMMon_Start: vcpu-0: worldID=4238
2014-07-13T19:59:22.069Z| vcpu-1| I120: VMMon_Start: vcpu-1: worldID=4240
The different world IDs as well as the VM's Cartel ID can also be seen in the vmkernel.log:
2014-07-13T19:59:21.979Z cpu1:4237)World: vm 4238: 1421: Starting world vmm0:MyVirtualMachine with flags 8
2014-07-13T19:59:21.992Z cpu1:4237)World: vm 4240: 1421: Starting world vmm1:MyVirtualMachine with flags 8
Hope this helps.
André