Sorry folks I wasn't very clear in my descriptions, the advice I was given was that side to side rotation (looking left and right) and tilting forward and back movements (looking up and down) were OK but that the stretch where one ear is lifted skyward while the other moves towards the shoulder (looking straight ahead but making the world tilt) is apparently not a great idea. Having a peculiarly big and heavy head I'm wary about this stuff!
Ah. Thank you for clarifying. I honestly don't know... I think a certain amount of range of motion is needed that way in the neck muscles but I could see where it would be easy to overdo it and put undue stress on upper cervical vertebrae. I think I'll do some research!