is he considered as an A-list actor now?

I wouldn't say he was quite there yet, but when an English actor becomes famous in the states, I think that's enough to say they've "made it".

A- at best

in terms of ability and talent, he's easily A-list

but A-list isn't about talent. it's about 'popularity'

in that sense, I'd say he's in the realm of A-list but I don't think even his Cornetto movies were able to make much money in the States

Simon, Edgar and Nick are all amazing but they won't be able to pull in 100s and 100s of millions