Holden Astra 2001: Uneven tyre wear

MY 2001 Holden Astra CD developed what seemed like a wheel-bearing noise at 35,000km. The mechanics at two Holden dealerships couldn't find the problem so I went to a Beaurepaire tyre outlet where I was told I needed new tyres even though the old tyres still appeared in good roadworthy condition. It was explained to me that the rear tyres had a wear pattern they described as the barber's-pole effect and that it could have been minimised had the tyres been rotated front to rear.