In my view I have an input, a span and a button like so:
Had the same problem and after a few experiments I've settled on writing
This way input is bound to the blue scope, which is exactly what you wanted.
Other way is to initialise phoneNumber with a true-ish value. Try $scope.phoneNumber= '123';
- worked fine for me.
Angular seems to walk up the scope tree looking for an attribute to bind to. If nothing's found - it binds to the inner-most scope, red scope in your pic. As other answer suggests - this red scope is created by ng-include, as a child of controller's $scope.