Bolivian rams-some of my favs-they're pretty peaceful. I have had trouble keeping more than one in the same tank without aggression. But to answer your question, they go well with any peaceful tetras, platys, mollies, corys, etc. Pretty much any peaceful tropical community fish.
Friendly advice-the lighter the substrate, the better they show their colors. My bolivian with black substrate turned very dark. My bolivian in my daughter's very bright tank looks like a typical bolivian, nice light colors, etc. Same temp, no
ammonia, no nitrites, nitrates 5-20.