This question assumes the following:
- SSL is used to verify the identity of the site, and provide a second layer of encryption
- jCryption 3.0 is used to encrypt any sensitive data sent between the client and server, even over SSL
- The server that the browser posts to is a load balancer (running a vulnerable version of openssl), which decrypts the incoming traffic and sends it on to a web server for further processing
From my understanding, someone performing a Heartbleed attack on the vulnerable load balancer would potentially only be able to uncover encrypted username & password data, or the server's private key from memory.