In the past Doubletree affiliate hotels earned points the same as other Hilton Hotels. See, e.g.:
http://www.flyertalk.com/forum/hilto...ffiliate+hotel
One of the Special Offers listed for the hotel is the double/triple points promo currently in place. The hotel is also listed as a category 5 for redemptions. I don't think you will have any problem receiving points but they probably aren't able to guarantee all the brand standards of a Doubletree at the current time.