WordNet records no synonym and no antonym for a-list. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a list of names of specially favored people
“the boss gave me his A-list of people we should try to recruit”
Synonyms, antonyms and the broader and narrower relations for a-list come from Princeton University’s WordNet. Full sources and licences.