Hi Simon
Having read Pete Brown's book "Hops and Glory" ... in which he recreated the effects on a cask of (19th Century style) IPA when transporting it from Burton to India ... aiming to follow the route an East India Company cutter would have, back in the day i.e. by sea, around the Cape of Good Hope, crossing the equator twice ... I believe that transporting (live, not pasteurised) beer
can have an effect on the flavours.
But the way that Madiera wine producers have studied and learnt to recreate the similar effects on their products (see
"Estufagem process" there (link)) without needing to involve motion, would suggest the differences are mostly caused by the variations in temperatures that might be experienced during the journey (though motion may well influence the rates of such changes occurring)
So if some cask of Bitter somewhere has been taken from the brewery cold store, put on a truck and delivered to a pub and placed in the pub cellar (at similar storage temps to the brewery cold store), all within a working day, to be tapped and served once it's all re-settled ... then the chances are it will taste very similarly to how it would had you had a pint at the brewery tap. But if the cask had been taken from the brewery cold store to a storage yard, where it was stacked with lots of others (out in the sunshine perhaps), for a few weeks and then put on another truck to be taken to the cellar of the pub it was to be served from ... then I suppose things may well have changed inside that cask in the meantime
Cheers, PhilB