I have no experiences with Jenkins and Talend but as far as I know Jenkins is about to build the job at night or when it is supposed to do that. The recent versions of Talend provides a maven or ant build script for the jobs but not for the build process to build the job source code. Keep in mind Talend is a Java code generator and you have always 2 chained builds: Build the Java code and build the job classes.
The first very important build step can not be done with standard build tools at the moment. I would be happy if Talend would decide to provide an ant task or a maven nature to do that.
If you have an enterprise version and a commandline running, you could trigger from Jenkins via telnet the commandline to build the jobs but I don not know if Jenkins would be able to do that.
