Okay, quickest and best is going to be the Publix in Regency Plaza on Vineland Ave. From the Wyndham Bonnet Creek main entrance/exit area:
Turn right onto Buena Vista Drive, staying in the right lane which almost immediately exits onto SR536. Again stay in the right lane which will become the entrance ramp for I-4 and follow the signs onto I-4 East toward Orlando (in other words, follow the ramp OVER the highway). Once you get onto I-4, stay in the right lane which becomes an exit only lane yet again. Proceed down the exit ramp to the traffic light and when the light is green, proceed straight through the light onto Vineland Ave. Continue about 1.25 miles (you will pass the Mary Queen of the Universe Shrine, Premium Outlets and Dixie Stampede. The Publix will be in the shopping plaza on your left just past the McDonalds.