According to latest Hilton HHonors T&Cs :

"A Member may earn Base Points for up to two rooms per stay, if all eligible charges for both rooms are paid on one folio. Base Points will be earned for all eligible folio charges incurred on both rooms. The term "eligible folio charges" is defined below. Bonus Points issued on Base Points, including tier bonuses (15%, 25% or 50%, depending on Member tier), Bonus Points earned through the HHonors Points and HHonors Points Earning Style Option and double or triple Base point promotions, will apply to the total Base point credit earned for both rooms. For any other bonuses, including HHonors Marketing Partner Bonus Points and other promotional bonuses, Bonus Points will be awarded on one room only. For purposes of obtaining tier status, a Member will receive stay and night credit for one room only. For purposes of earning miles for stays, miles may only be earned on one room only."

Be sure to book with phone app for triple points for stays oct-dec 2016

Hope I helped