How to patch this part of wall?

Question

I ripped out a stud wall and this hole is what remains. Can this area be filled in with bonding?

Answer 1

You want Thistle Hardwall really, rather than Bonding. Hardwall is for jobs like old Victorian brick that will suck water out of Bonding too quickly.
You could wet it down a day or two in advance & help with some thinned PVA and then Bonding, but Hardwall is more suited to the task.

You then might be best to skim the whole section rather than trying to get a match at the join, but that will also depend on what that bit of wall is coated with. Skimming modern vinyl emulsion is possible but needs some prep. You need to sand it to kill the surface texture, then wash it down thoroughly. Sugar soap would be best, but 'Fairy Up liquid' [as the missus calls it] will do at a push.

Answer 2

Is that large white surface next to the hole drywall? If so, or it is something else that can be removed, it may look better to remove that partial covering and put one full piece of new drywall covering the whole space.

If "bonding" means plaster or spackle or drywall compound or "Bondo", then it will not look good, and may shrink while drying, rendering multiple coats necessary.