"Creation team" or "creative team"
I would definitely go with creative. My reason is that "creative" is an adjective and "creation" is a noun, so it just sounds better.
google results
- creative team 552,000,000
- creation team 196,000,000
- "creative team" 8,930,000
- "creation team" 187,000
Personally, I've never heard people talk about the creation team.