As long as your glider does not get too warm in the combined pouch it should be fine. I expect that getting too warm might be a problem if both pouches are double layer fleece but if they are single layer it should be fine.
If your bonding pouch has a strap that can be removed, you can also hang it in the cage in place of the sleeping pouch. Your glider will sleep in it just as he would a regular cage pouch and all you will need to do each day is take the pouch out, zip it closed and attach the strap.
Just be very careful to unzip it when you put the pouch in the cage for the night.