In Taste by Roald Dahl, what was bet on both sides

Mike Schofield bet that Richard Pratt would not be able to guess the name of a special wine he had bought for the dinner.

Explanation:

Richard Pratt was a guest at a dinner organized by a stock broker named Mike Schofield. Richard Pratt was a gourmet. At the dinner, Mike Schofield presented a wine to Richard Pratt and challenged him to guess the name of the wine. In exchange for guessing correctly, Mike Schofield offered to give his daughter, Louise in marriage to Pratt. Pratt offered his two houses in case he failed at the challenge.

The result of the challenge was that Richard Pratt was able to guess correctly the name of the wine to Schofield's dismay. It was however later discovered that Pratt cheated as he had earlier been to Mr. Schofield's study where the wine was kept.