Hi Greer,
I love the Coronado Springs Resort! It's a sprawling property so it's not possible to be close to everything. For instance, those guests that want to be near the Dig Site pool complex will have a farther walk to the Pepper Market food court.
With a preferred room, you'll be placed in Casitas 1, 2, or 3.
Casitas 1 would be closest to the front bus stop outside El Centro. The proximity of Casitas 2 and 3 to bus stops will depend on your room location within these areas.
Theme park buses go in this order of bus stops begin at the Casitas, then head to Ranchos, Cabanas and El Centro.
If you want a ride to El Centro from your location, just hop on the first theme park bus that arrives at your bus stop.
Downtown Disney buses stop first at El Centro, then head to Casitas, Ranchos and finally Cabanas.
While requests are not guaranteed, you can certainly have a request placed on your reservation. If being close to a bus stop is your most important request, ask that your preferred room be close to a bus stop rather than putting in a preference of buildings.
Enjoy a wonderful vacation!