And who says no with bitcoin otherwise receiving donations? No one, I guess.
But perhaps, no one still opening up this idea in Patreon team that's why they don't have any donation address or we could assume that they are really strict when it comes on their Terms of Services

    -----------

So the least you could do is just PM your favorite creator and tell them you gladly want to tip him. I'm wondering now who's your pick, I mean he's surely good.