Like this
---------- main.css - template ---------------
<% if (bootstrap) { %>
<% if (compassBootstrap) { %>$icon-font-path: "/bower_components/bootstrap-sass-official/vendor/assets/fonts/bootstrap/";
@import 'bootstrap-sass-official/vendor/assets/stylesheets/bootstrap';
// bower:scss
// endbower
<% } else { %>
@import 'bootstrap/less/bootstrap';
<% } %>
<% } %>