What do Albanian Italians and Greek Italians think of each other?

I don’t know the answer as to what contemporary attitudes are. I do know two things though:

• The Arbëresh settlements in Italy were nowhere near the Griko settlements: the Arbëresh were much further to the north. There would have been a brief period when they shared church administration, before the Griko switched from Greek rite to Roman rite. But as far as I can tell, the two populations would barely have been aware of each other before the 20th century.
• The Griko really are Italian first (actually, given campanilismo, Salentini and Calabresi first), and Greek second or third. While Girolamo de Rada was the first Albanian patriot, I suspect the same is true of the Arbëresh. And as I posted at Nick Nicholas’ answer to How is the enmity between Greece and Albania different to that between Greece and Turkey?, enmity between Albanians and Greeks is a fairly recent thing—especially as the Arbëresh were originally Orthodox.

So if there’s any bad blood in Italy, it’ll be by people paying attention to what’s been happening in the Balkans, and who feel a very strong bond to what’s happening back there. I’m not saying it’s impossible, but I’d be surprised if it’s a big thing.

That aside, folklore enthusiasm and minority status would certainly be bringing Arbëresh and Griko together nowadays, whether as language advocates or as music performers. Those people, who are the vanguard of preserving their respective identities, would have much more cause to regard each other as allies within Italy.