After searching through multiple sources, there doesnt seem to be a specific term for a group of racing bikes. However, there are terms for groups of riders in a race, such as:

• Peloton: The main group of riders in a road race. This group is also commonly referred to as the field, bunch, or pack.
• Bunch: The main cluster of riders in a race. Also called the group, pack, field, or peloton.
• Gruppetto: A group of cyclists that rides together in the mountain stages of a race.

While there isnt a specific term for a group of racing bikes, these terms can be used to refer to the group of riders and their bikes as a whole.