Scheduled Maintenance Coverage

Recently, I took my 2006 BMWx3 into the dealership where I purchased the vehicle and have consistently had it maintened. (Not knowing about cars and car maintenance, I agree to BMW's suggested maintenance measures each time a suggestion for service is brought to my attention during the scheduled maintenance visits.) During this past maintenance visit, I was told the tires should be rotated. I had it done. After leaving the dealership I heard a thunderous noise at the front right side of the vehicle making it nearly impossible for those inside the vehicle to abide the noise. I took the vehicle back within the next few days. A service technican went for a ride in the vehicle with my husband. He maintained that it was a tire issue(he advised my husband that they raised the car to check, could not find a problem -- it wasn't the bearings -- and indicated that the car was safe to drive). The diagnosis was tire noise from the rotation. About 2000 miles and two months later, the thunderous noise having never abated, I took the car in for spark replacement (as scheduled) and indicated again that the noise continued to be objectionable, a significant audio issue inside the vehicle, and asked if there was some way to solve the problem. Another service technician drove the vehicle. I was immediately called and advised that the right front wheel bearing was damaged and perhaps the knuckle "siezed". I'm perplexed and frustrated. Is wheel bearing maintenance typically part of the an overall vehicle maintenance program? Thank you for a response.