Yes I distinctly remember using Terminal's tabs on snow leopard (10.6), confirmed by [0]. Also, I believe 256color was available in that release, though I'm less sure.
[0]: https://stackoverflow.com/questions/6736602/how-do-i-set-mac...
[0]: https://stackoverflow.com/questions/6736602/how-do-i-set-mac...
I'm 90% sure that's not accurate. It's had tabs for quite a while.