A lot of machine learning positions require a PhD, especially if you're going for big companies like Google. The most important thing though, as usual in the tech field, is demonstrating your expertize. You can do so in a number of ways:
- Work on your own projects and contribute to open source code.
- Get an internship if you can.
- Pick some data sets and do some interesting analysis on them.
- Join machine learning competitions like the ones from Kaggle.
- If you don't have a PhD but want to demonstrate PhD-level expertize, there's always the possibility of getting your papers published in peer-reviewed journals.
Also, it's also a good idea to attend machine learning workshops and events to network with professionals in the field.