Immigration Issues/Marriage certificate for J-2 or F-2 visa
I have been admitted to a university in the US and will receive either an F-1 or J-1 visa. I'm currently engaged to be married, but from various reason relating to Israeli law, will not be officially married. However, we are planning issue a "Certificate of Registered Domestic Partnership", to unify bank accounts, my Fiance is changing her last name to mine, and we have no problem to get married by court once we get to the US.
Will the embassy in Tel-Aviv accept this, in order to issue my fiance a visa? Or do I have to be registered as married in Israel as well?
The US Embassy can only recognize marriages that are recognized under US Immigration law. A Certificate of Registered Domestic Partnership does not sound like a recognized marital relationship under US Immigration law. The fact that she changed her name and all that is not material because the marriage is not a valid marriage under immigration law.
If she cannot marry you before leaving, try to see if she can obtain a tourist visa (B1/B2). If she can get the tourist visa then she can fly into the US, get married to you, and change status to J2/F2.
If she is refused the tourist visa, you must wait until you can marry her in Isreal, return there to marry, and apply for J2/F2 visa for her.