Yep it works.
switchport trunk native vlan 3997
3997 is a vlan I don't use. Once I did the change I could pass vlan 1 traffic as well through the BNT switch. It does not work as long as the pvid is 1, no matter what change you do in the portgroup. This is because Native VLAN ID on ESXi/ESX VST Mode is not supported, which means pvid 1 for vlan 1 will pass thru only a port in untagged/access mode. Thanks for your response.