But isn't any non-literal interpretation way too subjective to be of any real use? In the case of interpreting the Bible, we are so far removed from the context in which it was written much of the actual meaning must be lost. Certainly the interpretation of most allegorical passages could well be well wide of the mark - the original writers were desert tribesmen living in a massively different world.
If you're reading Beowulf in the modern translated version with no knowledge of the original language with all it's subtleties and wordplay can you really be said to understand the finer points of what the poet was trying to say on a particular subject? Were they joking? Being serious? Perhaps they was referring to some cultural trope which was common at the time of writing but has been long lost? Even with the translation (say of the King James version; the definitive English language translation) much of the symbolism 'translated' (added?) by the translator will be lost as our culture evolves (if you don't believe me, go and stand in front of a Pre-Raphelite painting, write down what it says to you and the read the interpretation given by the painters or contemporaries themselves - you'd be surprised how different they will be and they're not that far removed from us in the timeline of human history).
I'm always intrigued by the interpretation of religious texts. Who chooses which bit is to be taken literally and which is allegorical? Who decides what's relevant to the modern world and what's not? Or perhaps it's some sort of free-for-all of divine revelation where everyone believes what bits they want?