Under the IHG Rewards Club Global Membership T&C's
#9 Points for Stays
At U.S. and Canadian hotels (except InterContinental® Alliance Resorts), you can collect points or miles on all Eligible Charges for multiple hotel rooms (less than 10) provided those rooms are used in conjunction with the member's stay at the same hotel, and that their IHG® Rewards Club member number is recorded on each reservation, or the charges from those multiple room reservations are referred to on the hotel room bill associated with the member's reservation.
Yes, you will receive points for more than one room booked at the hotel if you put your rewards club membership number on each room reservation.
These T&C's are on IHG's website.