Drupal Commons with Bootstrap

I have a site installed with Commons and I’ve created a subtheme of the
commons theme. We would like to change the design with BOOTSTRAP for the
public side and still using AT theme to continue with the commons
functionality.

To switch theme we find the module themekey that feet with our need. I have
installed it and configure it to use a Bootstrap theme for anonymous users
and my subtheme of commons (AT theme) for connected user.

When I activate this new functionality the bootstrap theme is appearing but
Totally Blank and there is no html generated.

Do you have any idea what are the step i need to do to achieve that?

Do I need to change some part of commons so my anonymous Home page call the
bootstrap theme for anonymous user and the commons theme when my user is
logged in?

Thank you for your advice !