I think it depends on the concentration that you want. But when I worked in a restaurant we used about 2 tablespoons to a gallon to wipe down counters, and then just left it to evaporate. If you were going to rinse the trays afterward, I think I might use a little more than that.
However, you should be aware that bleach and ammonia mix to make a deadly gas that can damage our lungs, and I would assume rabbit lungs as well, and urine has an ammonia component. I would be very careful to use bleach in a well ventilated area and rinse well before returning the trays to the cages.
If you make the combination gas you can't smell it, but your chest will feel tight, your throat, eyes, and nose will burn, and you will start coughing--I have done it, bleaching a nasty bathroom floor. If you feel that way, get fresh air immeadiately.