You're in NJ- anything is possible! lol
Seriously, if Rutherford was recently reassessed, it's possible that they did increase that much- especially if the house was undervalued prior to the assessment. While I don't think it would be unreasonable for you to ask to see the tax bills for the two years, there's nothing saying that the landlord has to show them to you- you always have the option of moving out. Of course, since he used the taxes as the excuse for the increase, one would think he'd be OK with showing the bills to you.