Maybe read through the thread "ITA Airways on other Sky team Alliance" that usually hovers around the top of this forum. It's a catalogue of disappointment and frustration.

ITA may well be a member of SkyTeam, but it has not established any form of even the most limited relationship with more than a small handful of other members. Delta isn't one of them.

While it's possible relationships are being established, it's unlikely any will be consummated before ITA waves goodbye to SkyTeam.