Don't be fooled by the name because there are exclusions. Routine maintenance not defect-related and outside the control of the automakers are not covered in bumper to bumper warranties. For example, some bumper to bumper warranties do not cover tires, while others do not cover seat belts or headlights.
Keep in mind that bumper to bumper warranties vary depending on the dealership and warranty coverage, so look into your paperwork and the fine print before agreeing to pay for a bumper to bumper plan.