You must put it in ALL views. Currently the design principle is each view should describe exactly what you see on the screen.
It was a decision based on my past experiences where I have tried some frameworks that didn't do that (You would declare the tab once and each child view would be automatically included within that frame), which was confusing because the same code would render differently depending on context.
I personally thought making each view completely stateless is more appropriate for the approach Jasonette is taking, just like how html web pages do. But if you have different ideas or feedback please share.
BTW if you don't like the redundancy, you could declare the tab bar as a mixin and use them in all views.