I believe that almost any certification is a good thing. It helps prove that you have at least some level of understanding of a product or system. Going through the education is valuable and you more than likely might learn at least one or two things you did not know before and some of that knowledge & skills are likely to be transportable to other systems/services.
Certification is always a better idea for progress in your carreer. Yes Avaya certification will help u in your job.
All the best.