Edit: I just received an email from AmEx as follows…

It’s easy to redeem your bonus

STEP 1: Save this offer to your card
STEP 2: Spend $500 at one or a combination of these participating Velocity Partners:

Virgin Austrlia
Spend online.
Only valid for flights booked online.

Microsoft
Spend instore.
Spend online or instore.
Plus, purchase with Microsoft via the Velocity eStore and get an additional 4 points per dollar you spend

BP
Spend instore.

Hertz
Spend online or instore.
Rentals must be paid and returned to a participating location by 10 December 2017 to be eligible for this offer.

STEP 3: Be rewarded with 5,000 bonus Velocity Points.

Not sure if targeted but whilst signing up to the Rebel Sport offer this morning I noticed I had this offer too on my Velocity Escape primary card.

Save the offer to your eligible Card and spend $500 or more, in one or more eligible transactions at BP, Hertz, Microsoft or Virgin Australia by 10/12/17 to receive 5,000 Velocity Points. Limited to 8,000 Cards. Exclusions Apply.

T&C:

Please note for BP:
Valid in-store only.
Offer valid at American Express accepting locations only.
Excludes purchases of commercial fuel or bulk fuel.
Excludes purchases via BP Fuel card or BPMe mobile app.

Please note for Hertz:
Valid in-store and online at participating locations in Australia.
Payments must be made in-store at participating locations or online at hertz.com.au. Only online payments for rentals collected at participating locations are eligible for the offer.
Excludes payments via third parties such as travel agencies or online aggregators.
Rentals must be collected and returned to a participating location by offer end date to be eligible for the offer.
Excludes ACE Car Rentals, Firefly, Flexicar & Hertz 24/7.

Please note for Microsoft:
Valid in-store and online.
Excludes Skype & Bing purchases.
Excludes pre-ordered items where the release date is after offer end date.

Please note for Virgin Australia:
Only valid for flights booked online at the Australian version of virginaustralia.com which are paid for in Australian Dollars. Flights must be within or departing Australia.
Excludes payments for all other products such as hotels, holiday packages, cruises, charters, car hire, cargo, insurance, transfers, parking, Lounge membership, Velocity Frequent Flyer.
Excludes flights booked via call centres, airport locations, ticket offices, travel agents and online aggregators.

Offer valid at Australian locations and websites.
You must be enrolled in Velocity Frequent Flyer program and have an active loyalty account to receive the points.
Supplementary Cards are not eligible for this offer.
Points are not redeemable for cash.
Points should appear on your billing statement within 5 business days from qualifying spend but may take up to 90 days from offer end date.
Points will not be applied to your Account if it has been suspended or cancelled.
Points may be reversed if your qualifying purchase is refunded or cancelled.
Full Offer Terms available here.