Don't feel bad, HurtingDad, I often gave my son money with good intentions on where it might be spent and it almost always went to drugs.
I even just took him some groceries from a store near his place....and he returned what he could for cash. Arghh.
In the end, I would just take him for a meal sometimes or give him socks and underwear and leave it at that. He knew where help was and how to get there, so that always helped me deal with the sadness of him living on the street.
I'm so glad you both got to a meeting. It helps when both people are working on recovery together because it will help you and your wife understand each other better and make your decisions more mutual.
Your son is in my prayers, that he soon will find a better path.
Hugs