Sorry, I meant to add the others. They too are called "brother- and sister-in-law." You may also have a "mother-in-law" and a "father-in-law." Your wife's family are sometimes referred to collectively as your "in-laws."
I wasn't sure what you meant in your original post by "in general." I've never heard the term "sibling-in-law." The term "in-laws" is sometimes used to include all generations. However, if you say, "we're having dinner with the in-laws tomorrow," or "the in-laws are coming for the week-end," we're usually referring to our spouse's mother and father.