An update.
I took the car to AMC in Garret Lane who are the local BMW specialist. On leaving it with them they said these things are to a certain extent a matter of judgment, and it's easy to confuse wheel bearing wear with other things. (I'm not so sure on that one, IMHO. ;-))
Now I know the common thing to wear first is the bottom balljoints on these cars, and often at the sort of mileage that mine's done, but this shows up as wheel wobble at speed, and mine doesn't.
They've just phoned up. No wear or play anywhere - apart from a *tiny* amount on one inner track rod end swivel - the one on the rack. Not a fail and not likely to need relacment for another 50,000 miles (their words).
The other fails were rear brake pads worn to less than 1.5 mm thick. They're all better than 3mm.
Parking brake lever has no reserve. Rubbish, says the specialist.
Advisory. Both read discs worn. Within maker's tolerance says the specialist.
They're going to MOT it and change the brake fluid as the 'clock' symbol on the dash indicates. For 75 quid.
Sound I complain to VOSA? I've used the same MOT place many times before, but it's changed hands recently. And they did quickly offer to do the work needed after it failed...
A wheel bearing change costs about 300 quid on this car and it's not a common failure. Chances are they'd have claimed to 'adjust' it.
I'm first going to phone them and ask for my money back. I'll post the result.