On sheet music, I think you'd just indicate pitchbend with the standard glissando notation - usually the word "gliss" in small letters, and a straight or wavy line between the lower and upper notes. You wouldn't want to try to notate pitchbend as an amount of wheel rotation, because the amount would vary depending on how the patch was programmed.
For mod wheel, you'd need to come up with your own notation. I'd use a wavy line over the staff that lasts the duration of the modulation, and add a little "mod" over the line, with a note in the score explaining what that means. If you wanted to indicate a varying amount of modulation (for example, you want the modulation to gradually increase to the max, then decrease down to zero), I'd probably use a line that starts low and angles up to the max, then back, so it would form a sort of pyramidal shape. Again, you'd need to explain this with a note in the score.
That's the usual procedure when you need to come up with a non-standard notation - invent something that makes sense, then explain it in a note.
Of course, the transcribers here on the board may know of a more standard or accepted way to notate mod wheel; maybe they can chime in.