There is one for Common Lisp too https://github.com/m2ym/optima

Yes, I've used it, and it's quite nice. But it's not quite the same. In Elixir (and of course Erlang), pattern matching is pervasive. You use it when defining functions by defining multiple heads, each with a different patter. You can also use it when binding variables. For example:

{:ok, result} = compute_data(some_value, another_value)

If compute_data doesn't return a pair where the first value is :ok, it will throw an error.

Not by a long shot, Emacs Lisp is the most widely used Lisp dialect, by far. Clojure isn't even close.