First of all I finished watching the series a few months ago but I keep coming back to key scenes. There is still a lot to take in and a lot of names and characters that would probably take multiple viewings to fully get. I stumbled across this site on Google and, I like what I see.

But anyway:

First how did Phil (and Vito's wife) know about the first incident? I assume Sal Iacuzzo might be involved? It wasn't specified whose crew he was in though?

Secondly: The incident with the security guard. Tony specifically says that the information stays in those four walls. The people present are:

Tony, Christopher, Paulie, Carlo, Bobby, Patsy, Silvio and the one bald guy hanging in the back who I don't know.

Someone else speculated that it was Carlo, since he apparently had good relations with NY (when was this?) which would end after the Fat Dom incident. Plus he was the most vehement about taking Vito out. Thus he would have the most reason to tell Phil.

I would immediately rule out Tony (obviously), Silvio, Patsy (he said he didn't care) and Bobby. Christopher could be rebellious but he wouldn't take it outside the family for something like this (and in fact he was later pissed about Phil taking Vito out without permission).

I had suspected Paulie because he had spread Cifaretto's joke about Ginny, but again it was pointed out that by this time he was not interested in stirring up trouble, that was during prison when he was not in the best mood.

Well the bald guy in standing in the background could be the fly on the wall

I'm assuming the rumor spread the words on the street and of course the guys who told Chris when they met in AA meeting and the guys who saw Vito in the gay club when Vito got busted... so everybody spread the word...that's how wives know and they love to gossip about it....so Vito disappeared when they're looking for him so the obvious they think "Must be true".

I think it was Carmela and Rosalie Aprile who spilled the beans to other housewives after what Meadow told them.

Yeah and that coupled with Sal Iacuzzo telling everybody in NY about it. He was made, don't forget that. It's gonna lead to Phil easily.

Bingo.