If a hiv married couple are on hiv medications would it better to use a condom for safe sex?

Yes but clarify: I am assuming you are referring to one member of the couple having HIV and is on medication. Condom use is never 100% protective in preventing the spread of sexually transmitted diseases, however, a condom use is better than not using anything. Another member asked about use of a female and male condom; this would also be beneficial but not 100% protective.

Yes: Just because both partners have HIV doesn't mean it's the same strain. There is a phenomenon called " swarming" where a persons wild type virus is replaced by another. It is important.