TL:DR:
Yes!
Campaigns > Detail > Support a Team Campaign > Select Team Campaign > Click "Supporting a Team Campaign"
The Details
As long as your individual campaign is NOT already connected to a Team Campaign, you can convert your individual campaign into a campaign supporting a team effort.
On your campaign dashboard, navigate to Detail and click "Supporting a Team Campaign".
Choose the team you wish to support - and click support!Once complete, your fundraising totals will be reflected in the overall team total!