Wife on spouse visa with child child - council housing

[z4ydi]

I am British. My wife give birth to our first child early Dec 2010 while waiting for Visa appeal to go through after a refusal. Her spouse visa has been approved in Dec and we handed in her passport for visa together with my son's app for ROA - I am expecting them to join me in the UK soon. My question is:
I am working full time and have been on a housing list for over 8 years but as single person I am still at the bottom of the list. when my wife comes over to the UK can I inform the Housing Dep of my 2 months old British child (as a change of circumstance) and not effect my wife's ILR in the future?
Secondly how much will this help me get a council house - I work full time and live in Barnet, London.