No. If you are married filing separately, you are not eligible for the Premium Tax Credit unless you lived apart from your spouse for the last 6 months of the year or were a victim of domestic violence.
As for the HRA, it will depend.
"When your employer offers or provides you an HRA, your eligibility for Marketplace savings is determined by:
- The type of HRA — check the letter you got from your employer
- The dollar amount your employer will contribute to the HRA
- Your household income
- If other household members can use the HRA"