How do property tax breaks for seniors work with co-ownership of a home with a younger spouse?

This bit from the Texas Comptroller site indicates a surviving spouse under 65 can get the benefit even after the over 65 spouse dies, which wouldn't make sense unless both owners were able to get the exemption as soon as one spouse turns 65:

To qualify for the age 65 or older local option exemption, the owner must be age 65 or older and live in the house. If the age 65 or older homeowner dies, the surviving spouse may continue to receive the local option exemption if the surviving spouse is age 55 or older at the time of death and lives in and owns the home and applies for the exemption.

This is the behavior I'd expect based on how a similar exemption works in my home state (Colorado).

I'm not seeing any specifics for non-spouse joint-owners.

I would think, since Texas is a community property state, even if your wife's name was the only one on the deed you would still be considered an owner of the house (assuming it was acquired while married).

I emailed the Comptroller's office out of curiosity and heard back:

You are correct, as long as one spouse is 65 years of age or older, the property would qualify for the exemption as long as it meets the qualifications of a residence homestead as well.

If the property is owned by two non-spouses, the person 65 or older would qualify for 50% of the exemption amount.