MyBookTable appears to work correctly with the most recent version of Yoast's XML Sitemaps. If you are unable to see your books on the sitemap, be sure that you do not have the Books post type disabled on the Post Types section of the Yoast XML Sitemaps settings page.
By the way, that xml sitemap link you provided is showing a 404 error. Are you sure there is not something wrong with your Yoast setup?