Guest traffic was visible when the VM was in NAT mode, but when switched to Bridged mode traffic went straight through with LS unaware. I suppose LS was only sniffing the standard adapters, though this could have been improved since.

That's likely because VMWare Workstation's bridge mode likely injects into the networking stack at the same point that Little Snitch does.

I was only trialing VMWare before, so unfortunately I can't test this anymore.

Heads up that VMWare Fusion has a free version on Mac as of this month. :)