Re,
I think i figure out this topic.
To create a user based Term in Custom Taxonomy, i’ve created a meta attached to the term (new WP 4.4 feature) ‘author’ which contains the logged in user ID :
add_term_meta($term_id,'author',get_current_user_id());
and then to retrieve the user who has created the term :
$author = get_the_author_meta( 'user_nicename', intval(get_term_meta($term_id,'author')) );
I think it’s the best way to do it.
cheers !