Welcome back, Simon2! I've seen the AI companion thing advertised in different ways (and apps) on T.T., and I could see the potential allurement.
When the novelty wears off, you can break free. You can create other virtual assistants just by consulting the 'benign' versions of AI, like Chat GPT. It needn't be personalized, as it's a soul-less robot anyway.
Take opportunity to explore why it is that you feel you need this now. How are needs not being met, or what typical pressures, stressors or negative emotions are you escaping from via the AI assistant?
If not telling your wife helps to create that shame-free space to overcome this, then go for it. It is a struggle few women can- or are willing to understand. Sometimes we create an unnecessary burden (or worse) they were never meant to carry, and often times we do so only to selfishly relieve our own consciences. We feel better, while their world is shattered*.
(*On the other hand, some relationships are made stronger afterward, so each person must choose for themselves what's best for their relationship).
But you can very much break free, just as you did with porn use. It just takes one decision at a time. Not white-knuckled abstinence, but a mindful hard look at what it really is (mechanically aided fantasy), and that you really don't need it.
Wishing you the best in overcoming this robot with lipstick on it.