Can you mate with Queen and Bishop versus King?

Yes. King. And rectangle.

I could only think @Zunayed_781038 was alluding to the lack of a White king in my previous diagram (which was deliberate). Perhaps he could explain; but in words of not too many syllables for @KieferSmith's benefit.

A bishop mate with queen assisting.

Here's another way to do a queen+bishop mate

But you can't force that mate with the material OP specifies.

Not always. Try mating in 5 from here:

And you should be able to make it in 4 from here

Of couse not. But it's something to keep an eye out for.

If you have any difficulty, you can always study how the grandmasters do it.

Just got a checkmate with the queen and bishop which was satisfying

Don't know what I was thinking about when I wrote that. The position could easily be a forced mate.