JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://github.com/makeusabrew/bootbox/releases/download/v4.1.0/bootbox.min.js"></script>
<script src="http://tinymce.cachefly.net/4.1/tinymce.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">
<a class="btn btn-primary btn-large" data-toggle="modal" data-target=".modal">Launch bootstrap modal (works)</a>
<a class="btn btn-primary btn-large" onclick="bb()">Launch bootbox modal (not working properly)</a>

<div class="modal fade">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
             <a class="close" data-dismiss="modal">×</a>
             <h3>Bootstrap modal</h3>
         </div>
         <div class="modal-body">
             <h4>Text in a modal</h4>
			 <textarea name="content"><p>Some content in a Tiny MCE editor, lovely.</p></textarea>
         </div>
         <div class="modal-footer">
             <a href="#" class="btn btn-success">Call to action</a>
             <a href="#" class="btn" data-dismiss="modal">Close</a>
         </div>
        </div>
    </div>
</div>

JavaScript

$(document).ready(function() {

	tinymce.init({
		selector: "textarea",
		width:      '100%',
		height:     270,
		plugins:    [ "anchor link" ],
		statusbar:  false,
		menubar:    false,
		toolbar:    "link anchor | alignleft aligncenter alignright alignjustify",
		rel_list:   [ { title: 'Lightbox', value: 'lightbox' } ]
	});
});

window.bb = function () {
	console.log('bb');
    var d = bootbox.dialog({
      message: "<p>The textarea below should appear as a tinyMCE editor, but it doesn't.</p><textarea id=\"sandro\" class=\"sandro\" name=\"content\">",
      title: "Bootbox modal",
      buttons: {
        cancelButton: {
          label:     "Close",
          className: "btn-danger",
        },
        okButton: {
          label:     "Ok",
          className: "btn-success",
        }
      }
    });
    d.on("shown.bs.modal", function() {
		console.log('bootbox modal is now visible');
		tinymce.execCommand('mceAddControl',false,'sandro'); // doesn't appear to have any effect
	});
}