You need a degree + X years of experience to get in the door unless you can corrupt somebody in management. I'm sure a portfolio is valuable as well. What you have created is an important part of your background, just as where you went to school and where you have worked in the past is an important part of your background. A portfolio is likely to be given more weight by technical reviewers who can judge it properly, while HR is likely to care more about work background and education.
In short: A good CV gets you through HR so the engineers have a chance to look at your portfolio.