Protocol Droid said:

Furthermore, ESB and ROTJ it seem like the Rebellion doesn't know who Yoda is. As Senators in the Republic, the Rebel leaders would know about any Jedi who were prominant in the war.

How could you get this from the two film you mentioned? What Senators or rebel leaders or anyone in the rebellion mentioned knowing or not knowing Yoda?

At what point in TESB or ROTJ did Yoda present himself to anyone other than Luke, Ben, or R2-D2 for someone to not know whom he was?

If any of the Rebellion leaders knew Yoda, they would have mentioned to Luke that he's a little green creature who talks backwards. Luke wouldn't have been fooled by Yoda's "I'm not Yoda" act on Dagobah.