As long it is firm and still upright you won't need to re-pot it. Most bromeliads don't need a lot of root room. When the pups are large enough to remove, that is when you will need to worry about potting up.

Most potting soils work, but it depends on the situation. You will want something well draining, so not just the 'super soil' or that stuff. Nicer and more loose potting soil should be fine.
-andy