I'm house sitting for some people and a couple of their plants don't look great. What kind of plants are they and is it too late?

They are Pothos. The first one looks like it may have gotten too dry. The 2nd looks like it has had too much to drink.

Many housesitters tend to overwater plants in their care. Were the upended wine bottles your idea or the owners? How often do they empty into the pots? When you stick your finger in the soil, how does it feel?

Either under or overwatering, or too cold.

These are Epipremnum aureums. If they were being grown outdoors in lots of bright light, air movement from wind, and warm sun they could handle a lot of water. As houseplants, not so much.
Were they like this when you got there as a sitter? or did it happen in your care?
Its really looks like a watering issue

I'd get the second one away from the heat register on the floor. If you want to save them, take cuttings about 1.5" below a node with a couple of leaves on each piece and pop that end into a jar of water. After roots are about 2-3" long, get a pot that's not too large for the cuttings and using regular potting soil pot them up.

Otherwise, just clean them up by getting rid of the dead leaves, let the soil get pretty dry and water only then. You can tell when the soil has gone past too dry when the edges of the leaves begin to curl under and the whole plant looks droopy.

Wow good catch I didn't even see the heating vent

Don't know how long the house sitting will last. It's good you have these pics, juuuussst in case the owner is unhappy with how the plants look when they return.