Absolutely! Any contributions you make have all kinds of great effects. In particular, it means that the companies you interview with can actually see some of your code in the wild, instead of just having to go off your assertions about how great you are or a few 45-minute coding sessions. It also shows that you are not just a coder, but a software engineer, capable of adding to an existing project, presumably working with its owners to ensure you are in line with their visions and values. It shows you are willing to contribute to a community, likely in a way that betters some part of the world, in your own time, which reflects well on you as a person.
I always appreciate it when a resume has a link to real code, like a Github account.
So, yes, I certainly would expect it to be to your benefit and worth your time.