no problems just make it easy for yourself and you claim the child benefit and tax creds, you can do both online
but for the tax creds you and your wife must fill the app form in, BUT ONLY YOU SHOULD MAKE A CLAIM (you should only tick the box where it asks you about making a claim) . your misses will need a national insurance number for you to claim the tax creds.
your allowed to claim any benefit your entitled to ( infact your wife could claim the benefits becuase she married to a british citizen, but like i said make it easy for yourself and get the money to go in your bank account)
i've claimed tax creds and child benefit, my wife had no problems getting ILR and Citizenship, and your wife shouldnt have any problems either. so get your claims in ASAP as some can only be back dated 3 months max.