At what speed did the wobble start. Other times when you felt a slight wobble that quit on it's own - what speed & had it just been serviced that time also.
You may want to find a place that can do a very high quality dynamic spin balance of the front tires while still on the vehicle (Jefferson Bus Lines or a larger local interstate trucking company etc. are some ideas)
Dick at Precision Frame & Alignment in Elk River 763-241-9474 may be a good first call for help. Motorhomes are one of his specialties.
A steering tie rod dampener type of aftermarket product may be the band-aid needed to give you piece of mind that it won't happen again. (Be sure the product doesn't limit your tight turning ability)