I was curious because it says you have to guarantee the booking using amex card:
Cardmember is required to book in advance by calling Taj Reservation Worldwide or via www.tajhotels.com ,www.Seleqtionshotels.com , www.vivantahotels.com or email at reservations@ihcltata.com. At the time of makingthe reservation, the Cardmember will need to guarantee the booking amount by using the American Express® CreditCard as applicable