As a closing post on the Synapse e-list maintained by ANAT, which focused on bio-art through May, Jens Hauser gave a very fine summary on what could be considered bio-art, and what is just art related to biology. I think he really cuts the line at the perfect point, by saying:
Where I do not follow the argument anymore is when it seems to come to define an art form through the topic it focuses on, while trying to push the term per se into the direction of tactical media art: art which addresses biopolitical issues can get along fine without using biotechnological means of expressions, and artists also use them without necessarily emphasizing current (bio)political trends.
And this is a viewpoint I really appreciate, having seen the same issue in media art for years: saying something about media, computers of cows does not produce media-art of bio-art. It’s just a statement.
I wish I could formalize my points in such a way as Jens does. You can read his complete post here for your enlightenment, which also elaborates on presentation issues regarding bio-art installations, which I’m facing myself.