Air China PhoenixMiles credit card gives double points for purchases, but keep in mind that they can be redeemed for Air China mileage only. It is better to consider credit card with rewards on all purchases and flexible redemption options. For example, it may be the Discover it® Miles credit card. Using this card, you will earn unlimited 1.5x miles for every dollar spent on all purchases all with no annual fee. All the miles that you’ve earned during your first year are matched at the end of the year (provided you are a new cardmember). So, if you earn 30,000 miles, you get 60,000 miles. Earned miles can be redeemed for any airline ticket or other travel expenses like hotel stays, cruises, car rentals and more.
Another option for you may be the Barclaycard Arrival Plus® World Elite Mastercard® credit card. This card comes with the offer of 70,000 bonus miles after you spend $5,000 in purchases within the first 90 days of account opening. You will earn 2X miles on all purchases.