Accommodation Offer: Discount 15% on the official website's "Best Rate with Breakfast" program for the day, an additional NT$500 free dining rebate per room per stay.
Catering Offer: Discount 15% on the a la carte menu at Buttermilk

Conditions:

Reservations need to be made at least 48 hours in advance.
Accommodation offer is not applicable on 3-6/6, 8-9/6, 3-5/9, 14-17/9, 10-12/10-10, 25-26/10, 13-14/12, 24-25/12, 30-31/12/2024; each card is limited to booking 3 rooms per day to enjoy the discount.
Catering Offer is not applicable on 11-12/5, 10/8, 14-17/9, 28-29/11, 24-25/12, 31/12/2024, and special festivals announced by the hotel
Applicable for VIB Super Card

See here