There is no doubt that your plants would have handled all ammonia from one Betta. Wisteria is a very fast growing plant and uses a lot of nutrients like ammonium. I can guarantee from what you've said that without Cycle or anything, you would not have a problem. Your Betta is a happy fish.
Good to know. And yes, he is one happy betta. He's just loving that bunch of Wisteria and hanging out in it all the time.
Animal testing is a terrible idea; they get all nervous and give the wrong answers.