US Airways is offering bonuses on converting hotel points to Dividend Miles during the month of May. There are (3) stackable bonuses:
General members get a 25% bonus on transfers
Dividend Miles Mastercard holders get a 25% bonus on transfers
Dividend Miles elite members get a 25% bonus on transfers
So a Dividend Miles elite member with a co-branded Mastercard gets a 75% bonus on transfers into US Airways from hotel programs.
Since the bonus is on top of any provided by the hotel partner themselves, a transfer of 20,000 Starpoints would yield 43,750 US Airways miles with a full 75% bonus.
Bonus miles will post each week starting May 16, and they will continue sweeping weekly through September 5 to catch any transfers that are slow to post. The full list of hotel transfer partners is here. Registration is required prior to initiating the transfer.