I think his cards would be more collectible and sought after if he was a Yankee, but I don't think it would have affected his HOF status at all, outside of a few more percentage points in the voting one way or another.
You look at his baseball reference page, and it looks like he had a long career, but his breakout year puts him at a bit of a late bloomer, and his last real solid year was in his early 30's.
A lot of his career was spent either waiting for him to realize his potential, or waiting for him to get back to the guy he used to be.
He may still get in, especially if Tony LaRussa takes up his cause one of these years.
