This is an excellent question. OFCCP jurisdiction with regard to subcontracts, vendors, etc. is very confusing often both within and outside of the agency. The core question is whether the contract or agreement is in furtherance of the federal work. If a company provides widgets and a third party vendor supplies the components, then that vendor is likely a subcontractor. If a third party vendor supplies new office furniture, that supplier is not likely a subcontractor and would not need to be notified. The same if you purchase new paper shredders or something like that from Amazon or Staples, for example. When in doubt, it is usually a good practice to include that language. Sec. 60-1.4 equal opportunity clause, requires language in "each of its Government contracts." The laws protecting individuals with disabilities and veterans have similar language.
You can use this OFCCP audit checklist to ensure you're doing what is required to maintain OFCCP's regulations including VEVRAA, Section 503, and EO 11246. Or request a demo to streamline your compliance and recruiting efforts.