Bass nirvana, to me, depends on whatever else is going on in the music at the time, and how intelligently the bassist has chosen his/her notes. It could be the simplest thing that shows that they're listening to and playing off their musical surroundings, making the music better.
We're all capable of reaching bass nirvana if we listen and think wisely.
If we're talking about the pinnacle of 'Olympic' bass playing, then Jaco's playing on 'Havona' with Weather Report is perfection to me.