Biolinum is designed for emphasis, e.g. of titles. You can also use it for short passages of text. For longer texts a serif font such as the Libertine should be used for readability. The Biolinum has the same vertical metrics and visual weight as the Libertine, so that it fits perfectly to the Libertine and can be also used for emphasizing within the body text.
Linux Biolinum Capitals and Linux Biolinum Keyboard don’t presently work with Pinyin. But the other styles do, as this sample of Linux Biolinum with Pinyin text shows.