Update: 99% Sure that Amazon Product Ads qualifies for 4x points. (posts as SPONSORED PR*AMZN.COM/BILL WA, categorized as SERVICE)

Switched from legacy business gold to the new Business Gold in early March. The card officially converted over in middle of March when the billing cycle ended. The first billing statement as the new Business Gold card cycled Mid Apr (this weekend). I can't see the line by line bonus detail yet (apparently i can only see the March billing statement) but by doing a quick armchair calculation, it does appear that Amazon Product Ads post as 4x spend.

More than 50% of my monthly spend is one single vendor (Amazon Product Ads) with the rest being scattered in different categories. So, based on the "pending" points compared with line item detail, it does give me confidence that, at least for now, there is a bonus for Amazon. I'll add the data point to the wiki but meanwhile does anyone know the best way to get duplicate Business Gold cards? I'll hit the $150k threshold within a few months

Edit: Below is bonus detail on legacy business gold card, and since amazon shows as 2x, i'm almost positive it will show as 4x on the new business gold.

Billing Statement with Legacy Business Card