gweniepooh, the zometa infusions given after cancer are usually more frequent in smaller doses. You won't be likely to have the same side effects as those of us taking Reclast (5mg zometa). You can ask for slower infusions giving the kidneys more time to process the drug. It is a good choice shouldn't affect spondylosis and may help protect from the damage sometime caused by RA and will protect your bones from any (unlikely) metastasis, while protecting you from any advancing osteopenia.
While there are no known drug interactions between the two. Using them together may increase the chance of experiencing flu like symptoms and/or bone pain. But your doctor will probably be adjusting the dose in that situation. Congratulation on your successful treatment and early catch.