I can not find the character of Erestor listed as played by anyone. In the book he only shows up in the Council of Elrond and in Elrond's going to the wedding party. So I don't know if he actually ever appears in the movies. Someone would have to check the credits on the EE FotR DVD or pirated TTT DVD to gain more info.
Sorry, but come again.
The "Erestor" image can be found here
Other Elves on these card sets, such as "Golradir" (where did THAT name come from?) are undoubtedly in the movie, though they were not in the credits. Or the book, for that matter
I actually checked the council scene and saw an elf next to Elrond that i believe might be Erestor. You see him when Elrond says "Bring forth the ring, Frodo." And in the extended scene when Boromir is walking towards where the ring is placed. Also he is the only elf other than Elrond wo stays sitting.