<?php 

function my_em_bookings_table_cols_template_coupon($template, $EM_Bookings_Table){
	$template['coupon_code'] = 'Coupon Name';
	return $template;
}
add_action('em_bookings_table_cols_template', 'my_em_bookings_table_cols_template_coupon',10,2);
 
function my_em_custom_booking_form_cols_coupon($val, $col, $EM_Booking, $EM_Bookings_Table, $csv){
	global $wpdb;
	if( $col == 'coupon_code' ){
		if ( $_REQUEST['view'] == 'attendees' || $_REQUEST['view'] == 'tickets'  ){
			$booking_meta = $wpdb->get_var('SELECT booking_meta FROM '.EM_BOOKINGS_TABLE.' WHERE booking_id='. absint($EM_Booking->booking_id) );	
			$booking_meta = unserialize( $booking_meta );
			$val = $booking_meta['coupon']['coupon_code'];//$EM_Booking->booking_meta['coupon']['coupon_code'];
		} else {
			$val = $EM_Booking->booking_meta['coupon']['coupon_code'];
		}
	}
 
	return $val;
}
add_filter('em_bookings_table_rows_col','my_em_custom_booking_form_cols_coupon', 10, 5);