i would say that salmon are a quite hardy fish, and sea bass can be after they have reached adulthood, however sea bass are not a hardy fish in their juvenile stages.
Endowed with an inborn liking for man
sea bass have been found to die from excess stress while in captivity while salmon have been found to do quite well in captivity.
salmon have a yolk sac that allows them to eat until they are big enough to eat commercial feed, however sea bass need multiple types of feed as they grow.
Able to breed freely
it is much easier to breed salmon as all you really need to do is mix the sperm and eggs in a bucket. they do this during spawn without much else to help them. however sea bass need added hormones to breed and their eggs are tiny and very hard to handle. they often will not breed in captivity.
Needful of only a minimal amount of feeding
it takes a lot more kinds of food to feed sea bass than it does salmon. and with the new GMO salmon they are able to gain much more weight per pounds of food than normal
overall i would say that salmon are much more fit for farming than sea bass for obvious reasons. salmon do much better in captivity and are in the end much more cheaper to produce.