Michelle,
Getting the reading as good with bifocal contacts as it was with reading glasses ove the top is a wee bit difficult. With the reading glasses we can put in any power we want but with the contacts, you are more restricted due to manufacturing considerations.
It sounds like you have centre distance lenses, so the outside circle or annulus is the reading part. Reading ability does decrease with, dare I say it, age and I think that your optom is concerned if he maximises the reading now to the highest possible level from a manufacturing point of view, you won't be able to increase it further when you get older.
However, you may quite rightly say you would rather have the bird in the hand rather than the bush and cross bridges when you come to them! In which case you could say to your optom to increase the power now and you'll see what happens in a few years!
Thats as much as I can say without knowing more details!
Lynn