This hook allows you to add a comment just below the review and the gravatar image section.

Source

File : /templates/review.php

Example :

function prefix_wp_travel_review_after_comment_text( $comment ) {
    echo '<p>This paragraph is added after comment text</p>'; //  Adds the content after comments.
}
add_action( 'wp_travel_review_after_comment_text', 'prefix_wp_travel_review_after_comment_text' );