Our vinyl floor install will need to be redone -- will new vinyl need to be used, or can the existing vinyl be reused?
The bubble doesn't necessarily mean it wasn't glued, but rather that air became trapped under the vinyl while it was being put down - which means that the people putting it down didn't do it properly.

When installing vinyl, it should be unrolled slowly, with even pressure being applied along the length of the floor as it's being unrolled (slow, tedious work) and then when it's down a floor roller should be used over the entire floor, working from the center to the edges, to push air out.



Big bubbles means this wasn't done - it was put down in a hurry.  If the adhesive has set up already, it is almost impossible that they'll be able to pull it up again w/o destroying the vinyl.

The underlayment won't need removal, but the existing vinyl will need to be removed and the underlayment cleaned and scraped smooth before the replacement is applied.