Drush Open_BaseDir Error
My solution was to add this line to my .bash_profile

alias drush='/usr/bin/php5 -c /home/000000/etc/drush.ini ~/bin/drush/drush.php'


It turns out the CLI on MediaTemples Grid Service uses a different PHP.ini file. So that line basically tells it to find your drush.ini file to override some settings. Make sure to replace the 000000 in with your server number. Thanks to kiamlaluno and MediaTemples support folks for the help.