First and foremost, keep in mind that there is no universal list of "yes and no" foods for pouchers. We're all different.
In my case, I've always been more of a tea person (in fact I drank gallons of it before my surgery, and still do!), but I would enjoy the occasional morning coffee or dessert latte from time to time--until I figured out that coffee gave me almost instant diarrhea with both the ilestomy and again with the pouch. I haven't tried drinking it in years; I suppose I could always try a bit again as food tolerances change over time, but I think I've actually lost my taste for it over the years anyway.
That being said, we are all different and there are many pouchers who drink coffee without issue. So my advice is to try it. It's the only way you'll know for sure whether or not it'll affect you. And that goes for pretty much any new food you might want to eat with your pouch. Remember, it's all trial and error.