Add an Additional Credit Card (First Approved Card Only), Get 15,000 Bonus AmEx/Qantas/Velocity Points @ American Express

Updating the post - Full Credit to @littlesoldier for sharing the below link.
Looks like most of the Amex primary card holders/types can get this offer from this link(americanexpress.com) and get 15000 Bonus AmEx/Qantas/Velocity Points for Adding an Additional Card.

List of Eligible Cards

15,000 Bonus Qantas Points

• The Qantas American Express Ultimate Card
• The Qantas American Express Discovery Card
• The Qantas American Express Premium Card
• The Qantas American Express Classic Card

15,000 Bonus Velocity Points

• The American Express Velocity Escape Card
• The American Express Velocity Gold Card
• The American Express Velocity Platinum Card

15,000 Bonus Membership Rewards Points

• The American Express Explorer® Credit Card
• The American Express® Platinum Edge Credit Card
• The American Express® Platinum Reserve Credit Card
• The American Express Essential® Credit Card
• The American Express® Gold Card
• The American Express® Green Card
• The American Express® Rewards Advantage Card
• The American Express® Platinum Rewards Credit Card
• The American Express® Gold Credit Card
• The American Express® Blue Credit Card
• The American Express® Platinum Card
• The American Express® Elevate Credit Card
• The American Express® Elevate Premium Credit Card
• The American Express® Platinum MoneyBack Credit Card
• The American Express® Cashback™ Credit Card

Just received this offer in my email for my Qantas Amex Ultimate Card.
Note that I already have 1 x additional card in my account.

Add an Additional Card by 11 April and receive 15,000 bonus Qantas Points on your first approved card.
Share one Account with an Additional Card at no extra cost.
Plus for a limited time, receive 15,000 bonus Qantas Points and share the love.

https://www.americanexpress.com/en-au/credit-cards/manage-your-card/additional-card/15k/