Probably so, but in my experience "in the spotlight" is the more common expression. I'd take "under the spotlight" to mean "under a magnifier."
- A.
"under the spotlight" 733,000 (Google hits)
"in the spotlight" 4,720,000
Thinking in terms of a stage performance, which I believe is the origin, "in the spotlight" means calling attention selective to one performer or attraction among many. "Under the spotlight" means "to be closely examined."