skywards or velocity confusion!!??
 

Im looking for some advice. Im flying back to the UK from Melbourne at christmas and am a member of both Velocity (virgin blue) and skywards. I have noticed on the emirates website, as i go to book my flight, that i can enter either my virgin blue, or skywards number. Hence, i assume accumulate points for either. Does anyone have an experience of this, what might be the better deal. etc.
many thanks
craig