Send a copy of the confirmation email to the admin notification email address for Restaurant Reservations.

email-confirmation-copy-for-rtb.php

<?php
/**
 * Plugin Name: Email Confirmation Copy for Restaurant Reservations
 * Plugin URI: http://themeofthecrop.com
 * Description: Send a copy of the confirmation email to the admin notification email address.
 * Version: 0.0.1
 * Author: Theme of the Crop
 * Author URI: http://themeofthecrop.com
 * License:     GNU General Public License v2.0 or later
 * License URI: http://www.gnu.org/licenses/gpl-2.0.html
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU
 * General Public License as published by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write
 * to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */
defined( 'ABSPATH' ) || exit;

add_filter( 'rtb_notification_email_headers', 'eccrtb_add_admin_bcc', 10, 2 );
function eccrtb_add_admin_bcc( $headers, $notification ) {

	if ( $notification->event == 'pending_to_confirmed' ) {
		global $rtb_controller;
		$headers .= "Bcc: " . $rtb_controller->settings->get_setting( 'admin-email-address' ) . "\r\n";
	}

	return $headers;
}