As per titles guys
I have 220k MR points - Velocity currently giving 15% bonus to convert - however I dont have any existing virgin points (maybe 4000)
Etihad Guest I am Silver till May 2019 - currently have 52000 Etihad Guest Miles
I am based in Adelaide if that helps make a decision.
Preferably I want o convert before 15th April final cut of date for AMEX MR devaluation of points.
Hi cozmerk,
Your question is a bit like asking should I be buying an apple or an orange if I have money for only one. Ok bad analogy. 
You have to ask yourself what your goals are and what you are trying to get out of your hard earn pts. If you are just looking for domestic flights, Etihad Guest is well known to have some sweet spots on its award chart.
Velocity pts can be used on Singapore Airline flights and other partner airlines too.
Unless you provide a bit of background of your self, your needs, or plans, it’s rather hard for us to assist or comment.
Cheers.