Are Tasmania and Australia drifting apart?
No, there is no spreading ridge between Tasmania and Australia, they are both on the same continental block. East Gippsland almost broke off from the rest of Australia about 82 million years ago when a rift valley formed in Bass Strait, but the spreading stopped before it caused a proper break-up of Victoria! You can see the rift valley in some maps of the ocean floor off the Gippsland coast, it shows up as a deep part of the ocean.