I\'ve installed Symfony2, FOS User Bundle and Twitter Bootstrap.
Then I setup the /app/Resources/FOSUserBundle/views/layout.html.twig template to override FOSUserBun
Richard Miller's post has helped me achieve what I was trying to do.
http://richardmiller.co.uk/2013/02/18/symfony2-ajax-and-full-page-templates/
{% extends app.request.attributes.get('partial')
? '::ajax-layout.html.twig'
: '::full-layout.html.twig' %}
I couldn't get app.request.partial to work, and decided choosing based on xmlRequest wasn't ideal.