We’ve heard from multiple Australian PS4 owners this morning that they woke up to see a message from PlayStation as well as $15 in their account, which can be spent on absolutely anything with no minimum spend.
If you have the credit, you should see a notification/message on either PS4 or your companion mobile app. The credit will also automatically show up in your wallet.
Unfortunately, it isn’t clear what the stipulation is for those that are getting this voucher, and as with previous PlayStation promotions, it looks like not every PlayStation Plus voucher will get the credit. It could also just be a delay in them being sent out, but time will tell.