Bunin's style is notoriously rich and descriptive. He uses words like brushstrokes, to paint beautiful little snapshots of young, naive Russian farm girls, self conscious women and most beautifully perhaps, of nature and different distinctive aspects of each season. Other authors do this memorably as well - Turgenev, Tolstoy, Nabokov - but Bunin does it best. For example, in "Ignat" he conveys the quintessence of Russian winter with mere few sentences. Whoever has experienced winter on the Northern hemisphere - proper, true minus degrees winter, will feel a warm familiar sensation, reading these paragraphs. The smells, the way the light changes - its all described so accurately, that you can almost feel your toes getting chilly.
His main subject throughout his work was love. It is of course prevalent in "The grammar of love" as well. Bunin's characters are often longing, nostalgic, saying goodbye, betraying, being jealous - always feeling the strongest and frequently negative aspects of loving someone. In this book the stories are somewhat more erotic than in his other work. But the girls described are the same - pale, with dark eyes, flushed cheeks, know nothing of life yet or know too much to ever be truly happy and trustful; and the men too often blindfolded with passion.
If you are familiar with Bunin before you won't be disappointed in this book. But if you want to read only one book from him or are just getting started with his books, then I would rather suggest "Dark alleys" - in my opinion, his best stories collection, or "Life of Arseniev" - a strongly autobiographical memoir.