Will Augmentin (amoxicillin and clavulanate) work for a positive semen culture for enterrococcus faecalis? I've been on macrobid, zyvox, and ampicillin already.

It depends. It depends on what the antibiotic sensitivity testing showed on the culture that was done. If the sensitivity showed the bacteria was sensitive to Augmenting it should work. You should discuss this with your treating doctor.
Complex, see MD. Too complex for a brief reply. E. fecalis could be a contaminant, not actually responsible for any infection. And it's difficult to think of a genital infection (UTI, prostatitis, seminal vesciulitis, etc) that would not respond to the antibiotics you've already taken. If they didn't work, I doubt augmentin (amoxicillin and clavulanate) will. Discuss with your doctor and/or an infectious diseases specialist. Good luck!