Theme logo and site name
For that, you're going to want a custom template file (.tpl.php in D7, .html.twig in D8).

In Drupal 8, the logo and site name are contained within Bootstrap's block--system-branding-block.html.twig; in Drupal 7, they're set in Bootstrap's page.tpl.php. If you go into that file, you can change how those elements are rendered - just wrap them in the necessary  /  tags and you'll be good to go!