Depending which company you worked for in the FTSE100, some consultancies out there will "credit" you with your two years' experience and so bring you you in at year 3 level. This would most likely be true if you work for one of the financial institutions, perhaps some of the telecoms players...other companies may not be as well regarded as training grounds. I'm thinking of some of the retail companies out there. But even then it will vary.
If I were you, I'd shoot for +1...if the MCs want you but feel your traineeship is not up to the standard of their own, they can always come back with an entry-level offer.