Talend : Passing Parameters and Variables to ParentJob
You can pass context variables from the parent job to a child job but not the contrary.
At the end of your child job, you can send theses informations in a tBufferOutput.
In the parent job, you will get the data in the flow, after the tRunJob. You can then, with a tContextLoad, put theses values in the context, and transmit it to the log job.