I run and bike, I mostly go through phases where I focus on one then the other - for most of the past few years I have focussed on running (I did the Rotorua marathon last year) but this summer I am doing the She and Sun Latte triathlons and am doing a biking heavy training programme because I am really enjoying the biking. I am not really aware of a specific transfer of benefits in terms of strength or whatever from one kind of workout to the other - but it does have the benefit of weight control and aerobic fitness which does transfer - and stops me getting board with one kind of training.
Did you do Round the Bays?