It is strongly implied it was Wanda's influence, yes.
Full answer - contains spoilers
It is at least strongly implied but never stated explicitly, not that I remember at least. The biggest problem in answering your question with proofs is that the Avenger Disassembled arc is disassembled over multiple issues and things are implied through the long narration instead of explicitly said.
For example, there is no single dialog in Avenger Disassembled where someone states "It's been Wanda" -> everyone agree -> Wanda confesses. There are instead a few pages where Strange strongly suggest it's her fault, the Avengers refuse the idea and go talk with Wanda, only to end up in a fight with her. There is something more informative toward the end of House of M, if I remember correctly, but there is never a "full list of bad deeds"
Anyway, in the comics it goes this way:
There is a sequence of attacks and crazy stuff happening to the Avengers. Vision goes mad, She Hulk goes mad, Krees attack the Avenger Mansion, and so on.
It is lately discovered that this is due to Wanda.
At the same time frame of the other attacks, in the same exact comics, during the ongoing plot, we see Iron Man drunk during a conference at the UN.
First interesting fact: he claims to have never drunk anymore since a long time.
Second interesting fact: Wanda is here with Iron Man...while it's lately discovered that she was in Wondagore all the time.
Then, later, we have Iron Man discussing the issue with some of the other Avengers:
Now, as I wrote, I've found no moment in which Iron Man points his metallic finger at Wanda, says "You're responsbile for what happened at UN" and she replies "Yes".
But, honestly, I don't see how it could be any different: the story is about the Avengers and their destruction by Wanda, the entirety of Avenger #500 and Avenger #501 is dedicated to it, everything shown in them is about it. How could it even make sense that in the middle of one of the biggest Marvel blockbusters for the year, they choose to put four or five pages of a completely unrelated plot about a psychic attack to Iron Man to make him appear drunk, and then this plot disappears for good and is never continued in any way?