Alot goes into that. First of all, does your big bass only eat pellets? If it eats live on a regular basis I wouldnt risk it. If it only eats pellets and typically refuses to eat even shrimp or silversides, less risky. Always risk involved when mixing sizes that extreme. None of my cichla really like large prey. I have a 16" or so Orino and I dont think she would try a 4" meal unless she was very hungry. Another fish might jump all over it.
i wouldnt do it but like said above, alot of exceptions come into play. another thing, are these the only two fish that will be in the tank? if so, definitely wouldnt do it. might not eat him but beat him to death
my 10inch mono just gulped my 5.5 inch flagtail the other day and i dont feed live and my fish are all very fat.. i wouldnt dare try. but its already been said
i have a 12 inch bass with a 6 inch bass and they do fine no aggression at all but i have a friend with a 13" bass and he has gulped 10" gars hes taken snakeheads hes taken bichirs and even gradded his jardini and half swolled that then it died in the night so ultimately i would say would it be worth the risk? probably not