yeah .... it depends on which finger lands on the note i want to bend.
But during your practice routine .... you should plan out your fingering route in such a way that the bending note falls on the ring finger. Why?
Bending is done best when you have three fingers supporting together. Gives you strength an stability.
But of course you can't always do that because certain melody lines might not support that. You can also practice bending with all three fingers.
You can bend with pinky too, but i dun advise because there is a different purpose of using the pinky.
If you notice, most blues and rock riffs are played using the three finger position on the fingerboard. That's when most of the bending occurs.
The pinky is used in the four finger position on the fred board. This is commonly used for scaling ... speedy movements across the fretboard. Seldom bending.
Genres like Jazz and Classical guitar uses four finger position .... that is esteemed as the "proper" way of holding a fretboard. Of course, no way is the proper way.
But these different positions of 3 finger style, 4 finger style, whatever finger bending is really a study of ergonomics of the human hand. So do really what you are comfortable with. But most human hands are the same, so following conventional and proven methods might prove results.
Have fun.