Finally 'some' guidance today from the IRS in FAQs posted on their site.  FAQ #4 under Eligibility:

https://www.irs.gov/newsroom/2020-unemployment-compensation-exclusion-faqs

Q4. I'm married and don't file a joint return with my spouse. We live in a community property state. Are we eligible for the exclusion? (added April 29, 2021)
A4. Yes. Because you live in a community property state, you report half of your unemployment compensation and half of your spouse's unemployment compensation on your tax return and your spouse reports the other half of your unemployment compensation and half of his or her unemployment compensation on his or her tax return. You should exclude up to $10,200 on your tax return if your modified AGI is less than $150,000. Your spouse should exclude up to another $10,200 on his or her tax return if your spouse's modified AGI is less than $150,000. Neither of you should exclude more than the amount of unemployment compensation you report on your Schedule 1, Line 7.