They appear to be. I suggest calling Vanguard to double check.
Capital gains are exempt from New Jersey income tax if they are from a New Jersey qualified investment fund. A qualified investment fund must:
Related Resource:
Capital gains from fund trading or redemption of shares is not tax exempt federally. Here is a link to the applicable Vanguard page. See the notes at the bottom of the page.
Backed up the IRS publication here. Capital gains for the sale are taxable interest and dividends earned are not.