It's easy enough to transfer one work one into the other. As they are for the same employer, I'm surprised they aren't doing that anyway.
Personal pensions and work pensions aren't supposed to mix but you can do so by transferring it to a PRSA and then on to a work pension. But, it then becomes part of the work pension and its rules. By keeping it separate, you have the option of maturing it at a different time. It's quiet common for people to have a number of different pension plans, it gives you more options.
Steven
http://www.bluewaterfp.ie (www.bluewaterfp.ie)