Your spouse can apply for OHIP using your PGWP status and your employment letter stating you are working full time and will be employed for at least six months, plus 3 recent paystub. That's what Service Ontario required when my wife applied for OHIP as my dependent, same thing with my son.
My wife was able to apply for OHIP as my dependent.
See here:
https://www.ontario.ca/page/apply-ohip-and-get-health-card#section-2
Who qualifies
With certain exceptions, to qualify for OHIP, you must meet
all of the minimum qualifications listed below
plus at least 1 of the additional requirements.
To meet the minimum qualifications you must:
- be physically in Ontario for 153 days in any 12‑month period
- be physically in Ontario for at least 153 days of the first 183 days immediately after you began living in the province
- make Ontario your primary residence
You must
also meet at least
1 of the following additional requirements. You:
- are a Canadian citizen
- are an Indigenous person (registered under the federal Indian Act)
- are a permanent resident (formerly called a “landed immigrant”)
- are applying for permanent residence in Canada and:
- have submitted an application to Immigration, Refugees and Citizenship Canada (IRCC) and
- IRCC has confirmed they have reviewed the application and that you meet the eligibility requirements to apply (see document requirements) and
- you have not yet been denied
- are in Ontario on a valid work permit and are working full-timein Ontario, for an Ontario employer, for at least 6 months
- if you meet this requirement, your spouse and dependants may also qualify for OHIP
- if your work permit has expired but you hold “maintained status”, you may be eligible (please contact ServiceOntario for further information)