The only cards I know of that legitimately have 2 or more Pokémon teaming up (and not just having more than 1 Pokémon in the card art) are Tag Team GX and some LEGEND cards. I’ll list all of the current ones, not counting Rarer Full-Art/Rainbow/Golden/Secret reprints. :P
LEGEND:
Palkia & Dialga
Darkrai & Cresselia
Rayquaza & Deoxys
Kyogre & Groudon
Suicune & Entei
Raikou & Suicune
Entei & Raikou
Tag Team GX:
Mega Lopunny & Jigglypuff
Naganadel & Guzzlord
Reshiram & Zekrom
Arceus & Dialga & Palkia
Solgaleo & Lunala
Blastoise & Piplup
Charizard & Braixen
Venusaur & Snivy
Togepi & Cleffa & Igglybuff
Moltres & Zapdos & Articuno
Garchomp & Giratina
Mega Sableye & Tyranitar
Mewtwo & Mew
Raichu & Alolan Raichu
Slowpoke & Psyduck
Rowlett & Alolan Exeggutor
Umbreon & Darkrai
Espeon & Deoxys
Gardevoir & Sylveon
Lucario & Melmetal
Greninja & Zoroark
Marshadow & Machamp
Muk & Alolan Muk
Reshiram & Charizard
Pheromosa & Buzzwole
Eevee & Snorlax
Latias & Latios
Gengar & Mimikyu
Pikachu & Zekrom
Magikarp & Wailord
Celebi & Venusaur
Source, EXP
Hope I Helped!