Do you agree"

I partially agree with Wilde's statement, however I believe that the first part of the statement is essentially complimentary and serves only to qualify the second. I don't believe that Wilde thought that Balzac actually created life in the literal sense of the term. I believe that it was said in order to emphasize the fact that Balzac didn't copy life. To what extent Balzac imitated real life is debatable. In the preface to the Comedie Humaine Balzac writes:

"Chance is the greatest novelist in the world: one has only to study it in order to be fertile. French society was to be the historian, I had only to be the secretary... A writer could, if he adopted this method of rigorously, literal reproduction, become a more or less, faithful, happy...