In that context, there's no difference at all between the two.

They are very similar in your example. ‘Founding’ has the idea of creating something upon which future things can be built. ‘Establishing’ talks about creating something that will last, but not necessarily evolve. Harvard was founded. (It was small and unimportant originally, but is important now) The USA has founding fathers. (The country grew and became more important) The FBI was established. (‘Founded’ would sound wrong here. Laws typically establish things. )