We recently announced the preview of VNET Service Endpoints for Azure Service Bus. There is an important caveat for this feature: once you enable a service endpoint for Service Bus you cannot mix Standard and Premium tiers on that VNet. Because Service Bus Standard does not support VNets the endpoint will be restricted to Premium namespaces only and the VNet will block traffic to the Standard namespace. As a result, for now, please do not enable VNet service endpoints in applications that mix Standard and Premium Service Bus namespaces.
If you’re interested in mixing Premium and Standard Service Bus namespaces in the same VNet we’d like to hear from you.