Went back to a function i tried a night before when i think i was a bit tired and i must have slipped an error.
here it is:
// add tags in body
function tags_id_class($classes) {
global $post;
$tag_names = wp_get_post_tags ($post->ID, array('fields' => 'names' ) );
foreach ($tag_names as $tag)
$classes[] = $tag;
return $classes;
}
add_filter('body_class', 'tags_id_class');
Now when calling <body <php? body_class(); ?>>
it is outputting the tag name as well.
Hope it helps someone else.