NY non-residents are subject to NY income tax on NY-source income. NY-source income includes "...income derived from or connected with a business, trade, profession, or occupation carried on in New York State." Therefore your bonus is NY-source income.
https://www.tax.ny.gov/pubs_and_bulls/tg_bulletins/pit/ny_source_income_sole_proprietorship.htm#:~:t....
Therefore you must file a non-resident 2023 NY tax return reporting the bonus, in addition to your home state NJ tax return. Since NJ taxes its residents on all income received, the bonus is also taxable by NJ. However, you'll be able to claim a credit on your NJ return for the taxes paid to NY, so you won't be double-taxed.
In TurboTax, be sure to complete the non-resident state return before the home state return, so that the program can calculate and apply the credit.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
