The sidebar template should be rendered in the application template (not the index one) otherwise when you enter the /test route it doesn't show up.
Then in renderTemplate of App.TestRoute you can render the templates in the 2 outlets (sidebar and main).
App.TestRoute = Ember.Route.extend({
renderTemplate: function () {
this.render('test');
this.render('test_sidebar',{
into: 'sidebar',
outlet: 'sidebar'
});
}
});
See this jsbin example.
I hope it helps.