hmm... if that's the case, being that slow, either the wings are too small or the creature is minimal.
If it's the first, the flight maneuverability won't be that good, so it wouldn't make much sense in giving the creature bonuses for using the wings. My reasoning is: if the wings require that much concentration and effort just to do their job, they won't do that much difference or be at all useful when you're not concentrating on them.
If it's the latter, however, yes, it would make sense and the maneuverability could be the absolute best, but you have to take into account the maximum height/length a small creature can jump, no matter the result of the die...
EDIT: if it's a magical item, you could probably include the bonus to jump as a separate ability.