Mysql subquery not recognizing the subquery join table field
Your derived table is missing the extra field it is looking for try this: 

SELECT journeydata.dateTime,
alarmDetails
FROM 
journeydata
LEFT JOIN
    ( SELECT 
         GROUP_CONCAT( DISTINCT(
              IF(fence.fenceName IS NULL, alarmType.alarmName, 
                   CONCAT(alarmType.alarmName, 
                        '(',fence.fenceName,')'))
         )) AS alarmDetails,
         alarm.journeydataID as journeydataID   -- &lt;&lt;&lt; ADDED
      FROM alarm     
      JOIN alarmType
      ON alarm.alarmTypeID = alarmType.alarmTypeID
      LEFT JOIN fence
      ON alarm.fenceID=fence.fenceID
      WHERE alarm.associateID=6
      GROUP BY alarm.journeydataID
    ) AS alarmgroup
    ON journeydata.journeydataID=alarmgroup.journeydataID

WHERE journeydata.associateID=6


There might be more that needs fixing, but I would need a little time to look over the query and information you have provided.   Try this for now.

EDIT: Added the (untested) distinct grouping and formatting of alarmDetails as requested.