What did they tell you, how this promotion would work. At that place where you read that, I mean.
If patreon has a way of finding people by content, I did not yet find it. They are a parasite to social media, search engines and content hosters and they push their own agenda on top, instead of delivering a neutral subscribtion service.
So basically, it is a place to exist and have promotion link to, and not a place to be promoted at.
Oh, they do feature a handful of their biggest patreons as showcases on their home page. But if you get featured there, you already are famous to your audience. There is not even a button for similar developers or content topics for passive promotion like subscribestar has.