Mark
Looking at your previous posts your disposible is close to £400 before your payrise.Therefore with your substantial pay rise you would be able to repay your full 30k debts within five years so an IVA is not for you,in my opinion.
You could negotiate a repayment plan direct with your creditors,it's not too late or through a debt management plan.
To answer your question,yes all your disposible income is taken when in an IVA.
I would speak with Synergi and withdraw your IVA proposal and ask for a refund,they will be entitled to keep a reasonable amount to cover their costs.
Regards
Andy Davie
IVA.co.uk Spokesperson
About me:
http://www.iva.co.uk/andy_davie_profile.asp
IVA Helpline: 0800 197 4838
http://www.iva.co.uk/iva_helpline.asp