It depends on what you are going for.. If you wait and see how the things go with your existing ram and it doesn't last long you could at that time go for a pair of bolivians. Since their tankmates would be the pleco and the rainbows, if you end up with a breeding pair you should be able to still have harmony in the the tank. From there, as long as you had the breeding pair in the tank, you would have to stock around them. Basically this just means if you wanted to change things up you'd need to make sure to pick new fish that wouldn't get in their way because you don't want to mess with breeding cichlids.
I would not mix two rams of the same species with another species in a tank this size, so if you want to add a bolivian while the german is still around I would only add one. You could always add another later. Even in a larger space the bolivians could pair up and bully the german. They are more likely to just keep to themselves if you have one of each.
I would not mix two rams of the same species with another species in a tank this size, so if you want to add a bolivian while the german is still around I would only add one. You could always add another later. Even in a larger space the bolivians could pair up and bully the german. They are more likely to just keep to themselves if you have one of each.