drush aegir and drupal
Yes there is: it's a two or three step process, but automatable.

Step 1) Create a Drush alias, or in Aegir terminology, 'context' for the site using drush provision-save (arguments)

Step 2) Install the site using drush @(site context name goes here) provision-install

Step 3) (optional but recommended) Verify the platform in the Aegir interface to have it automatically detect the site and 'import' it into the frontend so that you can do other things to it later via the web interface. You can also run this verification from the command-line with drush @hostmaster hosting-task @(platform context name goes here) verify

For specifics on the syntax of provision-save etc, see my article, "Manage your Aegir system from the command line": http://mig5.net/content/manage-your-aegir-system-command-line.