PrimeFaces Widgets are richer than what bootstrap provides so we will not wrap bootstrap widgets for sure. A JSF library would only need to wrap widgets of bootstrap to come up with a quick and dirty solution for JSF.
CSS part is the real value of bootstrap for us, for example the layout feature of bootstrap is really great and we’ve used the grid layout in a client project as it is. It doesn’t make sense to bloat your JSF view with components like <p:gridContainer /> since you can do the same with just adding a simple div easier. Your page will execute faster since there less components to process on server side.
The best way to integrate PrimeFaces and Bootstrap would be a PrimeFaces Theme by porting Bootstrap Look and Feel. PrimeFaces components are so easy to customize, we have applied the look of Bootstrap widgets to our own widgets easily, no new tags, no new components are necessary, just CSS magic.
Check out the Labs Showcase to see the Beta version of Bootstrap Theme in action.
Bootstrap theme will be available with the next themes release wagon soon. At the moment, you can build the theme from source to give a try.