What does Mr. Wolfsheim tell Nick about Gatsby and Tom?
I am not aware of any place in the book in which Wolfsheim tells Nick anything about Tom at all. There are a few times that Wolfsheim talks to Nick about Gatsby and one time he communicates with him in writing.
Meyer Wolfsheim first appears in Chapter IV, at lunch with Nick and Gatsby. When Gatsby excuses himself for a moment, Wolfsheim tells Nick that Gatsby is an "Oggsford man" (76) and that he is a "man of fine breeding" (76) who would never look at another man's wife.
Wolfsheim writes to Nick in Chapter IX, to tell Nick this is "one of the most terrible shocks" (174) of his life.
Finally, also in Chapter IX, Wolfsheim tells Nick that when he met Gatsby, he could not afford to buy clothes and had nothing to eat for a few days. He says, "I raised him up out of nothing, right out of the gutter..." (179) and that they were "always together" (179).