During the enablement of vSphere with Tanzu, users can specify the size (Tiny, Small, Medium and Large) which will then dictate the amount of CPU and Memory that is allocated for the Supervisor Control Plane VMs.
After vSphere with Tanzu has been successfully enabled, you will find that only a subset of the settings can be re-configured but the Size is not one of those settings.
There was a question recently asking if you could resize the resources for the Supervisor Control Plane VMs? Although the vSphere UI does not allow you to modify the Control Plane Size value, the vSphere with Tanzu REST API can be used to perform this operation.