Though ventricosa is an occasional culprit, an unlabeled plant off of a website like Amazon is more likely to be "ventrata." Additionally, your "2" plants may very well just be two growth points on one plant (unless when you repotted it you found them to actually be separate, with separate root systems; otherwise one may just be a large basal shoot off the other). Some people claim peat moss is a decent growing medium for Nepenthes, but I strongly recommend a sphagnum mix as you put them in, as most people will have them in a higher humidity condition or a less strict watering regime that peat moss will tend to stay soggy and anaerobic in. Sphagnum, especially with perlite, pumice, bark etc. mixed in stays more open and aerated.