While v0 uses your Vercel account to log in, it is not part of your Vercel Pro team. For example, If you have a Vercel Pro team with one member ($20) and are part of the v0 Premium plan ($20), you would pay $40 in total, monthly.
And then here’s a little more information on the credit system that has now be deprecated:
The legacy version of v0 currently available at v0.dev is being deprecated and credits are no longer available for purchase. You can still use any credits you have, but they will not renew. After January 16, 2025, v0.dev/chat will be the sole offering for all users.