Bathtub venting question

I am renovating an upstairs bathroom and have a question about moving the vent for the tub. The original drain for the tub vents to the roof. It was originally attched to a vent for the washing machine downstairs. The vent for the washing machine was attached to a T about 40" above the floor of the bathroom (It is the notched section on the studs). I moved the T down to about 6" above the floor to allow space for the wall (The T would be below the top of the tob). My question is, does the vent need to be moved above the tub and if I have to move the vent back up how can I install so that the walls will be close to flush against the studs, or is my change OK. Also can the electrical wire run around the vent pipe as in the picture?

Thanks,
Jon

As I understand it, the vent needs to be above the flood plane of the fixture it is attached to. Normally, since the drain for the tub may also serve as the sink drain, around 42" or so, so what you had was correct. Now, the vent can have some angles in it, so you can angle it closer to the middle of the stud wall to get it out of the way.