Can I do a product swap while I am waiting for my signup bonus to arrive?

Hi I applied for St George Amplify Visa to get 80,000 Qantas Points. now that I have spent 4,000 and awaiting for the sign up bonus. is it possible to change the reward system to amplify rewards so it can be more flexible? Thank you

some banks allow changes to credit card products over the phone, or online, or fill out a form and some dont.