What happens after Worlds division eliminations

After a winning alliance has been determined for each division in the HS Division at Worlds, does the tournament pit all 5 alliances against each other in order to determine an overall winner, or do they just declare each alliance the winner?

Here is how worlds works:
The high school at worlds is broken into 5 separate divisions, named Science, Technology, Engineering, Arts, Math. Each of these divisions has 1/5th of the teams in it. In the tournament, teams only interact with others in their group, as each division acts as its own tournament. After 10 qualification matches, the top 8 seeds pick 2 alliance partners. Teams that are not chosen are eliminated. After a best of 3 bracket, the winning alliance of the division is crowned. These top 5 alliances then compete in a round robin best of 1 tournament(each alliance plays each other). The two alliances with the best records then compete in a best of 3 to crown the world champion.