It depends on what actually is desired by the pair getting married. As the whole wedding photo thing is about sentimentality, you have to work on that aspect alone. Cant do anything "technical" in terms of content.
Try to get an idea of what the wedding dress actually looks like, and if possible in similar lighting condition. Since there will be incandescent light I would expect shadow here and there. Can make for a few good candid poses if she spends some time in the low light spot, but can be a pain on shutter speed.
HOWEVER I would suggest you contact the restaurant owner and ask if someone with a similar cell phone as yours can go around at various times of the day and take the best photos they can with it so they can send and you can see what the phone thinks its best for the lighting in terms of color, iso, shutter, etc.