captb747 thank you for the explanation re: crew bus aircraft to terminal. I understand the logistics are possibly difficult at LHR but my previous airline also flew into LHR and I don't recall every waiting for the bus. That was a good few years ago though and obviously the infrastructure at LHR has become increasingly over stretched.
VS should still be taking a look at what going wrong though as I'm sure they are being charged a hefty sum by the company providing the buses.