New Twiddle

components.my-svg.js

import Ember from 'ember';

export default Ember.Component.extend({
  click: function(evt) {
  	console.log('tagname', evt.target.tagName);
    if (evt.target && evt.target.tagName === 'polygon') {
    	alert('You clicked the SVG polygon element.');
    }
  },
  actions: {
    someAction() {
      console.log('Clicked!');
    }
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'ember.js/issues/13420'
});

templates.application.hbs

<h1>{{appName}}</h1>
<br>
{{my-svg}}
<br>
{{outlet}}

templates.components.my-svg.hbs

<svg>
	<polygon points="300,1007.5 300,1550 0,775 300,0 300,542.5 2050,542.5 2050,1007.5"></polygon>
</svg>
<h3 onclick={{action "someAction"}}>Fire action on click</h3>

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember-template-compiler.js"
  }
}