Bamboo doesn't substitute JIRA variables/parameters after integrating Bamboo with JIRA

I created a VCS Tagging task and tried to use the ${bamboo.jira.version} variable along with ${bamboo.buildResultKey} variable in the "Tag name" field. ${bamboo.buildResultKey} is getting substituted, but ${bamboo.jira.version} doesn't even though the variable name is in the list described under "Runtime, Plan and Global variables" link of the Tasks page.