Google have stated that they do not use analytics data in their ranking algorithms. Analytics is purely for the benefit of webmasters, to observe site usage.
Mathematically, that is not entirely correct. Bounce rate is a percentage of the number visitors that view only one page. A visitor that views two or more is not a bounce, but only counts as one non-bounce, regardless how many pages they view, or how long they stay.
Therefore, a visitor that spends an hour viewing 20 pages will not decrease the bounce rate any more than a visitor that spends 30 seconds viewing only 2 pages.