Science and intelligence may prove me wrong, but in my mind, your cables should be the same. I use DogStar mic cables now and I just invested in some DogHouse interconnects. It may be overkill, but I have the extra loot right now, so I play...
I think more than a few of us have thought about our recording rigs and forgotten our playback systems. I know I did for a long time, but recently I've been concentrating on my playback - what's the point of recording at such high-quality when you can't listen to it at the same high quality???
Anyways, to get back to your cable question, I think it would be wise to get some nice playback cables, but to get a full set of BumbleBees (or anything else) may be overkill??? The star-quads are quite good for most playback applications, seems a lot of folks use them... So you may not need or want the improvement.
My worthless thoughts,
Terry