For anyone wanting a heads up on what BT and ST are and what is the relationship between them, I recommend these articles by D.A. Carson and Richard Gaffin. (I should mention that both articles are hosted by BeginningwithMoses.org which is a great BT site).
Here is Carson’s conclusion:
The distinctions between systematic and biblical theology are perhaps more striking. Although both are text based, the ordering principles of the former are topical, logical, hierarchical, and as synchronic as possible; the ordering principles of the latter trace out the history of redemption, and are (ideally) profoundly inductive, comparative and as diachronic as possible. Systematic theology seeks to rearticulate what the Bible says in self-conscious engagement with (including confrontation with) the culture; biblical theology, though it cannot escape cultural influences, aims to be first and foremost inductive and descriptive, earning its normative power by the credibility of its results. Thus systematic theology tends to be a little further removed from the biblical text than does biblical theology, but a little closer to cultural engagement. Biblical theology tends to seek out the rationality and communicative genius of each literary genre; systematic theology tends to integrate the diverse rationalities in its pursuit of a large-scale, worldview-forming synthesis. In this sense, systematic theology tends to be a culminating discipline; biblical theology, though it is a worthy end in itself, tends to be a bridge discipline.