dianaro, in terms of recognition - Bocconi has a very high international reputation.
When an international student applies for a Master or even a job abroad, they OFTEN look at which is the best business/economics school in that country - in Italy it's Bocconi!
Whereas if you apply worldwide from York, I don't think it has the same recognition effect.
I know people from the UK who did BIEMF because they would have a higher chance getting into an investment bank, consulting or blue chip than doing a non-Top5 university in the UK.
While some professors have the Italian accent, they are highly renowned and respected throughout the economic community. Needless to say, one of its professors is currently head of state of the country.
I used to have your same concern, too, when I decided to study in a non-UK university, but in the end it is not the language quality of the courses that matters, but the professors intrinsically, the environment of the university, its connections, networks.
Bocconi is the gateway to any good company in Italy and in the world, if you're a good student.
If you're not a good student, you'll end up partying with rich parents' kids anyway and marry one of them anyway :P
Trust me, Bocconi is really good, very interdisciplinary, very "outside the box" and highly recognized in numerous fields.
Maybe York has a higher value WITHIN the United Kingdom.
BTW what is your origin/nationality?
It may be that if you're Italian and you want to chose a course ALSO to improve your technical English language simultaneously, then perhaps doing a Bachelor in the UK and then a Master at Bocconi could be a good alternative.
But apart from that, don't underestimate the importance of Bocconi in the international community, in academia, business, politics. Many leading Economists from other universities teach BIEMF as guest lecturers as well, including from Harvard and Scandinavian top 10.