JJeffrey answered the question and even provided the links with the first one linking exactly to the AA Newsroom; here it is again ->
https://news.aa.com/news/news-detail...3/default.aspx
Here's the direct quote from the Newsroom
Also starting in April, Admirals Club members traveling on JetBlue will be able to access Admirals Club lounges, including the newly opened lounge space at LaGuardia Airport (LGA). American’s Admirals Club lounges are membership-based lounges that feature complimentary amenities like food and beverages, Wi-Fi, business centers, and kids’ rooms.
As for Citi AA Executive, primary cardholder gets complimentary membership to AC so you can bring in immediate family or quest, and authorized users get access to the lounge (but are not members). See details on the card benefits details:
Only Citi® / AAdvantage® Executive World Elite Mastercard® primary credit cardmembers who are eighteen (18) years of age or older will receive full membership access privileges to Admirals Club® lounges. An authorized user of the Citi® / AAdvantage® Executive World Elite Mastercard® who is eighteen (18) years of age or older will receive access privileges to American Airlines Admirals Club® lounges. Full Admirals Club® membership privileges do not apply to a credit card authorized user. An Admirals Club® membership includes access to other airline lounges and clubs with which American Airlines may have reciprocal lounge or club access privileges.
So yes and yes to both of your questions.