The relationship of theology and Bible exegesis / translation is pretty complex imo.
A vested interest in theology (in the form of commitment to a particular doctrine, confession or sect) can obviously produce "bias". But a lack of interest in theology can be even worse, when scholars approaching the texts from a purely "scientific" (philological, linguistical, historical) angle fail to relate to the issues at stake, to the point of not even perceiving them sometimes. Nietzsche criticism of "disinterestedness" as the scientific form of the ascetic ideal (in Genealogy of morals) comes to mind: the "disinterested" exegete / translator often makes the text uninteresting. This is particularly true in translation I feel; you may translate "correctly" a text you don't like, but it is unlikely that you will serve it well.
An old Pentecostal pastor once told me: "the ideal Bible translator should be both an atheist and a born again Christian" -- which I interpreted as, being able to distantiate himself absolutely from the text and resonate with it deeply. I couldn't agree more. :)