Are tags for files serchable?

I seem to be having trouble querying for files by tag. Are tags for files not like tags for posts?

$args = array(
        'numberposts' => 10000,
        'tag' => 'training,timeline,resource',
        'orderby' => 'post_date',
        'order' => 'DESC',
    );

    $posts = get_posts($args);
    print_r($posts);

This retrieves posts with those tags but not files with those tags. Help?

http://wordpress.org/plugins/wp-filebase/