No. From what you just said JG (may I call you that? I have issues with people calling me WIE on other forums...), more surface area will increase the amount of bacteria. No, it will just spread them out more thinly, where they can be spread a little thicker. The bacteria population will stay the exact same, as long as the amount of food and the amount of oxygen is kept the same. Though an increase in oxygen will not increase the population by itself, nor will an increase in food (ammonia, nitrites, and sometimes, depending on if it is an anaerobic strain that is converting nitrates into nitrogen gas, nitrates) by itself increase the pop. Only an increase in both will increase the size of the population.
Though, more surface area will increase contact time, it will not increase the amount of bacteria, it will merely distribute them over a larger area.