The general contractor, or GC, manages the schedule, the site and the subcontracts. On a bid job, the GC collects prices from subcontractors and suppliers and sends one bid to the owner.
Example: four general contractors bid a school. A gym equipment supplier sends the same proposal to all four.
Your customer on most jobs is the GC, not the owner. Find out which GCs are bidding and send your price to each one. Write your proposal for the GC's estimator. That person has little time on bid day and needs your scope in plain words.