I've never kept Bolivian Rams, but I've got some Blue Rams and tetras in my 55. The only issue you may run into is feeding. My Rams are fairly timid/slow eaters, and the tetras will often eat all of the food faster than the Rams can. I've found if I drop flake food on the surface the tetras are distracted. Then I drop some small Ciclid pellets by the filter return, and the filter helps make them sink. The Rams will grab them on their way down.