I'm in the States and can distinguish *some* non-American English accents. I can tell Cockney from Liverpudlian from Scottish and NZ/Australia, but don't ask me to identify a person from Manchester vs. someone from Oxfordshire, or someone from Melbourne vs. someone from Auckland.
Then again, in my own country, I can't distinguish among Southern accents -- Georgians, Kentuckians, Virginians and Alabamans all sound alike to me. Ditto North Dakota vs. Minnesota vs. Wisconsin, or Boston vs. Rhode Island (and I'm *from* Boston!). So I wouldn't expect someone from outside the country to get those little nuances.