Yes, in Super Mario Party Jamboree there is a similar function to the Partner Mode from Super Mario Party. In this game, the "Partners" return, where a random character appears on the board and must be won through a mini-game to add them to your team. Each of these characters, also known as "Jamboree Buddies", has their own abilities and mini-games that must be played to win them and add them to your team.

There are 2 vs 2 battles, but everything cannot be played in teams. All content can be seen here:
https://www.youtube.com/watch

More specific question: Can you play as a team of two?