Thanks Mackle for quick response.
I had the exact scenario you described. I was in UK a decade back, and had a Lloyds issues AMEX card.

Was disappointed when I could not get a global transfer done on moving to USA due to my AMEX being issued by Lloyds.

I don't exactly remember how i applied for my Hilton AMEX (hilton or amex website), but that won't be hard to find out. I will also try to email AMEX support to confirm this. But still looking for some real example which would definitely help.