On flights to LHR I believe VS does the same thing BA does and applies surcharges to some (all?) partners flying to UK. You need to look at Delta flights to elsewhere. On ITA I have no idea what VS shows or doesn't show. At a minimum I'd probably look at the Flying Blue website and see if you see an award availability on the dates you are looking for. If FB cannot see anything I doubt VS is missing anything. If FB does show something and you cannot see online call in and see if the VS agents can see it. It is very possible to book partners with VS for lower surcharges. I just booked US>Madrid on KLM in J for 58.5k and $295 one way. Which was half the price in points than Flying Blue wanted.