The timing seems convenient enough that such a large disaster would be considered a punishment. I know that at the time of the eruption the Church wasn't formally established, but perhaps at some point afterwards, did some Pope or other sort of religious authority look at the story of what happened to Pompeii and create a connection between the dots?
I don't know if anyone saw it in connection to the crucifixion of Jesus, but the Sibylline Oracles, a collection of Jewish and Christian prophesies, connected it to a more recent event: the destruction of the Second Temple by the Romans in 70 CE, only 9 years before Vesuvius.
An evil storm of war will also come upon Jerusalem
from Italy, and it will sack the great Temple of God …
A leader of Rome [Titus] will come … who will burn
the Temple of Jerusalem with fire [and] at the same time slaughter
many men and destroy the great land of the Jews.
…
When a firebrand, turned away from a cleft in the earth [Vesuvius]
in the land of Italy, reaches to broad heaven
it will burn many cities and destroy men.
Much smoking ashes will fill the great sky
and showers will fall from heaven like red earth.
Know then the wrath of the heavenly God.
This article has a half-decent overview. But be wary of the other claims about the inscription and the garum, those seem sort of fishy to me (no pun intended).
http://members.bib-arch.org/publication.asp?Volume=36&ArticleID=6&Issue=4