They changed not too long ago.
Amplify Signature Frequent Flyer Credit Card | BankSA
*Amplify Qantas Bonus Points offer: The respective bonus points promotions are available when you apply and are approved for a new Amplify Platinum Qantas or Amplify Signature Qantas credit card between 24th January 2019 and 22nd May 2019, and spend the minimum amount of $4,000 on eligible purchases on an Amplify Signature Qantas credit card or $2,000 on eligible purchases on an Amplify Platinum Qantas credit card within 90 days from card approval. Eligible purchases do not include BPAY or BPAY equivalent transactions, fees, cash, cash equivalent transactions, refunds, balance transfers debited from the card account, government fees and ATO payments.
Existing customers who currently hold a Amplify Platinum or Amplify Signature card issued by St.George, Bank of Melbourne or BankSA, or who have held one in the last 12 months, are not eligible for this offer. The bonus points will be credited to your points balance within 12 weeks after the eligible spend criteria is met. Interest free days do not apply to credit cards with balance transfers, you'll be charged the applicable purchase rate on any spend that you make whilst you have an outstanding balance transfer.