JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.0-rc.0/angular.min.js"></script>
<div ng-app="app">
    <div>Inner: <inner>✔︎</inner></div>
    <div>Outer: <outer>✔</outer></div>
    <div>Workaround: <workaround>✔</workaround></div>
</div>

JavaScript

var app = angular.module('app', []);

app.directive('inner', function() {
    return {
        restrict: 'E',
        transclude: true,
        template: '<u ng-transclude></u>'
    };
});

app.directive('outer', function() {
    return {
        restrict: 'E',
        transclude: true,
        template: '<a href="#"><inner ng-transclude></inner></a>'
    };
});

app.directive('workaround', function() {
    return {
        restrict: 'E',
        transclude: true,
        template: '<a href="#"><inner><foo ng-transclude></foo></inner></a>'
    };
});