I'm aware of that - but Zepto and Backbone don't have a UI layer
If, however, you are referring to the weak link between Zepto-managed DOM and Backbone Views via hand-rolled render functions, then check out outback.js, a declarative data binding layer for Backbone in the same spirit as Knockout.js - well, more than spirit, the binding extensibility layer uses roughly the same API and much of the same documentation.