Originally Posted by xliioper

I'm not aware of any airlines that are still doing this. If you are thinking of Delta, again, they abandoned that practice and now DL Amex cardholders are only advertised as getting Zone 5 boarding priority as Delta no longer uses named boarding groups.
https://www.delta.com/us/en/check-in...rding-priority
https://global.americanexpress.com/c.../delta-reserve

UA and AA, like DL, all use number boarding groups. They do use terms like "Preferred" and "Priority" boarding for CC holders, but they don't try to call it "Zone 1" boarding.
https://www.united.com/en/us/fly/tra...g-process.html
https://www.aa.com/i18n/travel-info/...ng-process.jsp