Solved the issue. Anyone who may stumble on this it appears jQuery Tools overlay has a hard time with the data-rel attribute on the featured image. Instead I re-configured the jQuery to find the rel tag on the anchor before the featured image and call the post id on the rel tag.
WP Code:
<a rel="#<?php the_id(); ?>" href="#<?php the_id(); ?>" class="bio"><?php the_post_thumbnail('full'); ?></a>
jQuery:
// Team Bios Overlay
jQuery(document).ready(function() {
jQuery('a.bio[rel]').overlay({
mask: '#000',
effect: 'apple'
});
});
Hope this helps someone else with a similar scenario