I have ubuntu 12.04, kernel 3.5.0-31-generic, and Asus zenbook laptop ux51vza with hybrid graphics (it has both intel Ivybridge and nvidia 650m cards). I am using Bumblebee version 3.2.1 in order to switch between cards. optirun application_name works fine on my laptop, but when I log via "optirun ssh -Y user@server" and try to run any graphical application, it always uses the intel graphics (which I verified by running applications that print out the name of the graphics card used). Running optirun bash; and then launching ssh from the new shell, it still uses the intel card.
I would not normally care about using the nvidia card for ssh sessions, but for some (unresolved issues) some applications do not work with my intel card, not even when launched locally on my laptop (but they do work with nvidia card), and I need to use them over ssh.