I notice Man vs. Fiction has posted a bibliography of the books reviewed on the blog so far. I typically include bibliographic information with all my reviews.
Is bibliography important? I think it is a matter of context.
In academic or research settings where it is important to produce verifiable results, it is important.
In a context like this blog, it is not very important. One can find a book pretty easily online or on a library’s computerized catalog with just the title or author’s name. Readers of this blog aren’t likely to be helped by additional publishing information except possibly the year of publication. Some people are mainly interested in recent books, though obviously I’m not. A detailed bibliography is not necessary for a blog like this, but it is easy to include, so I do.