Do you have a reference for which portion of the IRA bill text you're referencing? I initially thought you meant the FHA rules coming out of the infrastructure bill, and don't see now any text about EV charging stations in the IRA.
The FHA rule coming out of the infrastructure bill seems to have language about "(c)
Connector type. All non-proprietary charging connectors must meet applicable industry standards. Each DCFC charging port must have a permanently attached Combined Charging System (CCS) Type 1 connector and must charge any CCS-compliant vehicle. For NEVI projects using FY22 funds, one or more DCFC charging port(s) may also have a permanently attached CHAdeMO connector (see
www.chademo.com). Each AC Level 2 charging port must have a permanently attached J1772 (incorporated by reference, see § 680.120) connector and must charge any J1772-compliant vehicle. One or more DCFC charging port(s) may also have a permanently attached proprietary connector." That would sort of imply that "non-proprietary CCS1" for the purposes of the infrastructure bill includes open-access to all CCS1 vehicles, and thus a private CS1 network charger wouldn't be a "non-proprietary CC1" charger for eligibility under the infrastructure bill grants Unless the text of the IRA provision over-rules that or doesn't have a non-proprietary CCS1 requirement, I suspect the same definition would be applied, and thus private CCS1 networks would similarly be excluded from any new grants, though obviously the actual text is what matters.
EDIT: Added the last couple sentences of the section, just for clarity--they're not relevant to the definition of "non-proprietary CCS1" for the rule, but they're a reminder that a stall to be covered may have other types of plugs available like Chademo or TPC, as long as it has CCS1 as a minimum.