IHG Rewards Club has added Hawaiian Airlines Hawaiian Miles to its roster of partner programs on January 9, 2014.
You can access IHG’s web page for airline partners here.
The number of Hawaiian miles depends of the hotel brand and the region:
2 miles per $1 USD or local currency equivalent paid on eligible charges at InterContinental Hotels & Resorts in the United States, Canada, Mexico, Latin America, and the Caribbean and at all Crowne Plaza® and Hotel Indigo® hotels worldwide
At Holiday Inn®, and Holiday Inn Express®, Staybridge Suites® and Candlewood Suites®, members can earn 1 mile per $1 USD or local currency equivalent paid on eligible charges.
At InterContinental® Hotels & Resorts outside of the United States, Canada, Mexico, Latin America, and the Caribbean and at all InterContinental Alliance Resorts worldwide, members can earn 500 miles per qualifying stay.
You should earn IHG Rewards Club points for your IHG stays. I would only credit to an airline program IF there is a very good promo for double/triple miles or some sort of partner program promotion.