This is what Bank of America says about income (for a college credit card):
You need not reveal income from alimony, child support, or separate maintenance payments. You may include income from your parents, summer job(s), savings, spouse, salary, and loans.
When applying, just find out what you can report as income.
They like to say income does not factor into FICO score, however, income determines how much credit you get, and that impacts you FICO (or at least your chances of getting the good cards). When reporting my income, I include everything I can.