My husband and his family were Assemblies of God. (They no longer are.)
I searched the Assemblies of God official website, but I don’t see any specific quote about this. But here is the Constitution of the Assemblies of God. Take a look at p. 7.
ministers.ag.org/pdf/2007ConstitutionBylaws.pdf
Based on the knowledge that I have from my husband’s experiences, and on reading through the various documents on the Assemblies of God website, I do not think that there would be any baptism required for the Lord’s Supper.
The Assemblies of God considers baptism a symbolic act, an “outer symbol of an inner transformation.” In the Assemblies of God, a person becomes a Christian when they ask Jesus into their heart to be their personal Savior. The Assemblies of God asks that only Christians receive Communion, and that would mean anyone, including children, and including Catholics, who have received Jesus as their personal Savior, is invited to participate in the Lord’s Supper.
(Catholics are forbidden by the Catholic Church from participating in non-Catholic communion services.)
BTW, I’m not sure what you mean by A of God “valid baptism,” unless you’re talking about baptism by immersion, which is the ONLY baptism that A of God accepts. A Catholic who wishes to join the A of God will be asked to be re-baptized by immersion before the congregation (public, not private). But again, this isn’t a requirement to receive communion. You will see plenty of little children receiving communion in the A of God, and these little ones generally aren’t baptized, as the A of God believes that baptism is a choice of the believer, not something that is imposed upon them by parents or anyone else.
You might want to google Assemblies of God and check out their official website, and then call someone on that website for an “official answer” to your query. Or call the pastor of a local A of God church in your city.
One more thing–I think it’s kind of funny that the A of God is making a very public campaign that they’re just a simple Christian community, no big heirarchy or politics, just church the way it was back in the New Testament–but the website and the Constitution makes it obvious that there is a huge organization, with multiple levels, rules, and regulations, behind the Assemblies of God. I am NOT criticizing this!–on the contrary, I believe strongly that the best Protestant churches SHOULD have a well-organized structure and denominational basis, and I distrust the non-denominational fellowships and home churches because it is too easy for bad teachings and even heresy to creep into these non-structured fellowships. It is also too easy for the non-denominational churches to become “personality churches,” where the pastor is the “star” and everyone has a feeling of intense loyalty to him/her.