You should notify your IP of the marriage as, presumably, you moved in together and none of your original income and expenditure would be accurate. Your new partner would not need to be made aware or divulge their income, although your IP would probably ask. This is because the new partner would be expected to bear their fair share of expenses. So, say you both earned roughly that same, you would both be expected to split household expenses 50 / 50. On, for instance, rent of £800 per month, you would be allowed half: £400 in your agreed expenses. This could increase your IVA payment. Without being given such details ( and there are many IVA's where partners never know or find out) the IP will assume this 50 / 50 split.
If you have moved in with your partner, rather than them moving in with you, you should also advise your IP of the change of address.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014 http://foggy.blogs.iva.co.uk