If you missed the FAQs regarding the bike classification, here is a quick recap:

Team bike refers to a higher tier of motorcycle that offers better performance and additional benefits compared to Rookie bikes. When you purchase a Team bike, you not only get a bike with improved stats but also unlock two upgradeable team staff members and receive sponsorship from the corresponding team. The team sponsorship provides better payment opportunities compared to the sponsorships available for Rookie bikes. Riding a Team bike allows you to progress further in the game and compete at higher levels.

You may refer to the video below for brief explanation of the Team bike.