Well surprise surprise the extended warranty company has wriggled out of things.
Apparently although wheel bearings are covered by the policy, any part is only covered if it fails and thereby causes the car to actually break down.
To achieve that I would have to have continued driving with an ever more noisy bearing until it suffered a catastrophic failure, endangering me and others and no doubt causing a more expensive recovery and repair.
Ah - but they would be able to wriggle out of that too. There's a clause which says if the driver keeps driving when it must have been obvious that there was a problem, then the warranty is invalid.
So their wheel bearing cover - in fact their cover for anything at all - only applies where there is a sudden part failure with no prior warning, which causes the vehicle to be undriveable. So that's quite a limited set of circumstances for £274 a year.
Others on here have counselled putting some money aside for repairs instead of buying expensive cover which might not be needed (or might not be applied). I will do so in future, and have asked for the warranty cancellation terms...maybe I can get a refund of sorts.
They also took from Friday till Monday late pm to tell me I wasn't covered, during which time my local garage did have time to repair it. I then had to wait until today for them to fit it in, which cost me £191.