First and foremost, ALWAYS CALL the BCC, never use the online REQUEST form because many are calling in and booking the sailings before the BCC even checks the online request forms.
The BCC offers 15% off the drink package, I'm not clear if it stacks with CC discount. Either way you need to call in, I would recommend calling BCC, ask if their 15% discount stacks with the CC and if no, ask for them to transfer you to reg X customer service so they can apply the CC discount.