Bale wouldn't be a certain starter for the current Barcelona side, but he would play a lot of football there because he is good enough. It is a moot point anyway, because he isn't the kind of player they would go for. They were reportedly interested in him as a left back, where he would shine, but he isn't exactly the kind of forward they usually go for.
Also, Xavi, Iniesta etc would walk into every team on the planet. Possibly not Xavi at 33, but a few years back that would be true.