If they truly have bloat, once they've stopped feeding, it's usually lights out. If you got the metro treatment going soon enough, you do have some chance. Changing water and metro treatments are the best approach I know but the odds are not high that they'll recover. The only other thing to consider is reducing stress on the fish while you're treating them. Not knowing how many fish are in the tank, it would be better for those unaffected (so far) be removed to limit their exposure but if the unaffected fish are significantly more numerous, that may be a problem.
Had you changed anything in their feeding routine, other than potentially overfeeding them. Increased male agression recently? I've had a little experience with tropheus getting bloat but never from simply overfeeding them. Sometimes after overfeeding tropheus, especially on dry foods, they can swell up and appear to have bloat but starving them for a couple days will take care of the problem if they don't actually have bloat. Do your fish have all the typical symptoms including cowering in the upper corners of the tank, gasping and uninterested in eating?