Anyone has experience registering for Amex Platinum Charge supplementary card benefits?

I recently got my new charge card and my partner has the supplementary card. I was able to register the hotel status benefit (eg SPG Gold and Hilton Honors Gold) however her card is not showing these option on
I checked the condition and clause again on website and Amex website confirms that these benefits are available to supplementary charge card holder. Just wondering if anyone else has experienced the same problem? When I called up Amex customer support they seem to be pretty clueless on the issue. I was told to call back again tomorrow but that doesn’t really sound confident to me.

I did it a year ago so do not have recent experience - but I assume you would have tried doing it with an individual log on for the supplementary charge card of your wife?