Senator Bob Menendez publically supports equal banking rights for cannabis businesses. Senator Menendez has not made many statements regarding his position on legalizing marijuana. 

S.1152 - SAFE Banking Act (2017-2018)

"Legal marijuana businesses need to be able to open a bank account, pay employees, take out credit cards, & write checks. The SAFE Banking Act is a game changer. It gives cannabis businesses access to basic banking services, making the industry safer and the future brighter." (August 12, 2019).

In a letter signed by a bipartisan group of Senators, Menendez called upon Appropriations Committee Chair and Vice Chair to request that they include a provision in the FY18 budget to prevent the DOJ from interfering in states that have legalized marijuana.
2/12/18
https://www.scribd.com/document/371449984/Bipartisan-Appropriations-Letter-on-Marijuana-Enforcement

When asked if Marijuana should be legalized or decriminalized, Menendez urged administration to respect state laws & submitted bill to study states that have legalized. Supports giving pot businesses access to banking services. https://www.ontheissues.org/Domestic/Robert_Menendez_Drugs.htm