I chose "I like the idea" because I see Greek mythology, and I like . That said, are you certain you want to use Greek mythology? 'Cause this tale commits what I frivolously hold as the cardinal sin of mythological adaptation: disregarding the character of the characters.
Now, take everything I say with a grain of salt, as some iconic stories came from attaching a foreign concept to a familiar name. I only point out that your Dionysus and Aphrodite do not act like Dionysus and Aphrodite, as these are two of the gods who'd care the least about saving the world, embodiments of hedonism that they are. Moreover, you wrote that they are looking for a new god of the world, but Greek mythology lacks any such god. The top god tends to be Zeus, but even he has limitations that the likes of Yahweh and Buddha do not endure.
I would recommend narrowing the stakes to strengthen your story: they need a new god of a specific thing, not of the world. To address the point raised by @kirschwassen, make it a thing that your protagonist is uniquely qualified to fill. If you use those two gods, you'll struggle to make it important to the world, so just focus on making it important to the narrative. If you can succeed in making us care about the characters, we'll learn to care about what they care about even if it's somewhat silly.
If you desire large stakes, you need to use bigger gods. Hecate, Zeus, Hades, Hera, Poseidon, etc. You gotta bring out the big dogs to work with world-threatening scenarios. Unless you write about an entirely different world, it'll be hard to make sense of fate swinging on the whims of the god of drunks and the goddess of sex.
There's some feedback. Hope it helps !