Yes, it certainly helps. But even for most subsidiaries of German companies in the U.S. it ranks relatively low on the priority list - except for translation agencies or call centers, for example.
However, for most career opportunities in this niche, it is more important that your education and professional experience / expertise meet the specific requirements of the job profile.
Many German communities offer budget-friendly German language classes for newcomers.
But don't wait to acquire or brush up on your German skills if you are still in the U.S. Serious proactive efforts and language certificates will look good on your "Lebenslauf" when you apply for employment with German companies.
Whatever your German language proficiency level - the Germany-USA Career Adviser team can help you take the next step: