Mayfair, it's more likely that your bank allowed the credit to your account immediately, the cheque wouldn't have actually cleared at that stage and technically could still have come back unpaid, this can happen at any time really, as previous poster said 'the process is there is no process' - it's dependent on timings and efficiencies of other banks in the chain so a case of how long is a piece of string...
Sorry OP - that isn't much help to you! If I were you I would ask your bank if they can credit the funds pending clearance, that's what happens when you lodge an Irish cheque (depending on your acc, for most accs) the monies are credited straight away even tho the cheque has not cleared at that point, it's done in good faith if you like.