Elixir is not homoiconic. They used to claim that based on a very unusual definition of homoiconicity, but they have removed those claims from their materials.
But Julia is, or not? If yes, why? (The only difference, as far as I can see, is that Julia AST is considerably simpler than Elixir's (a Julia struct with 3 fields, only two of which need to be present: head and args). Though admittedly, that counts a lot.