"rates among unvaccinated persons with a previous COVID-19 diagnosis were 29-fold lower (95% CI = 25.0–33.1) than rates among unvaccinated persons without a previous COVID-19 diagnosis in California and 14.7-fold lower (95% CI = 12.6–16.9) in New York. Rates among vaccinated persons who had had COVID-19 were 32.5-fold lower (95% CI = 27.5–37.6) than rates among unvaccinated persons without a previous COVID-19 diagnosis in California and 19.8-fold lower (95% CI = 16.2–23.5) in New York."

Asking for a "significant" difference is just using weasel words to note that each individual post-Delta study is not powered to detect a difference with those very small slices and no metanalysis having been completed yet. Every single study has shown a point estimate difference that is consistent with vaccination conferring additional protection on those who have previously recovered.