I guess so, Spark announces the model as the one from 1998, the same year Gillet switched from Ford to Alfa. But to be honest it's still not an evidence...
I'm not sure they switched effectively in 1998. More than that, I'm still not sure that a single of the road cars was sold with Alfa power. I know that Alfa doesn't supply the GTA engines alone, so Gillet has to buy complete cars, then resold them engineless. Since such a 147 GTA was for sale recently there, one can guess that its engine went into a Vertigo.
Here they quote 25 cars built overall.
The Alfa engine is associated with the Vertigo Streiff version, which is dated 2000 on the
official site