Indeed so Genghis and I recall a couple of years back during Farnborough/Fairford week, observing a B1 transitting between the two taking a fairly close look at Greenham.
Take the point made by others re. AWE, it is 4nm E right on the extended centreline of the westerly runway
Leaving that aside, the number of logistics/distribution operations that have and will set up on Greenham Park (the industrial site based on the south-side of the old airfield) testify to it's good transport links. Part of the place looks like a dockside at the moment, with stacked shipping containers covering quite a large area.