In The Great Gatsby, what do George Wilson and Tom Buchanan learn about their respective wives and how does each man react?

Both George Wilson and Tom Buchanan learn of their respective wives' infidelity, and they react in opposite ways.

Tom is large, athletic, wealthy, and confident to the point of being a bully. Wilson is "spiritless. . . anaemic," poor, and blond with light blue eyes, which in literature is sometimes associated with being weak, sensitive, and/ or bland.  

We first see the interplay of the two men's personalities in Chapter 2. Tom and Nick stop at Wilson's garage-cum-used car shop. After receiving a hearty slap on the shoulder from Tom, Wilson asks him,

"When are you going to sell me that car?"

"Next week; I've got my man working on it now."

"Works pretty slow, doesn't he?"

"No, he doesn't," said Tom coldly. "And if you feel that way about it, maybe I'd better sell it somewhere else after all."

"I don't mean that," explained Wilson quickly.

This tells us everything we need to know about these men's relationship. Tom knows Wilson needs the car, and insists on taking his sweet time just to show he can. Wilson has to put up with Tom's condescension because getting that car is critical to his financial survival.

Their relationships with their wives are also different. Tom treats his wife Daisy badly, but she stays with him, largely for financial security. Wilson is henpecked. Because Wilson lacks money, his wife doesn't respect him.

Both men learn, apparently on the same day, that their wives are having affairs.  

Tom, who we would expect to react with rage and perhaps violence, is, after his initial shock and anger, unruffled. He is sure he is a better man than Gatsby, his wife's lover, so he simply sets out to prove to Daisy that Gatsby is a fake, and is confident Daisy will never leave him.

George Wilson, who seemed incapable of standing up to his wife, reacts to the news that she has a lover swiftly and decisively. He decides to move her out West. When she puts up a fuss about this, he locks her in her room. After an even worse turn of events, he plans violence against her lover.

Arguably, the men's reactions show Wilson loves his wife—however inconvenient that love may be—while Tom does not love his wife. Tom just needs Daisy for certain things in his life, and he knows she needs him in the same way.