Regardless of the OCI in your warranty schedule (even if you have a 2/24 'free' service window), the owner is expected to check the oil level on a regular basis and add oil when needed. How often do you check your oil level? You should have caught this well before you tripped an oil light.
All manufacturers pretty much draw the line at 1qt per 1000mi when determining whether oil consumption is excessive. Yes it sucks and they absolutely do it to limit warranty claims for internal engine repair, but it is the norm. You'll likely need to lawyer up if you want them to do something at your rate of oil burn.
How often do you check your oil? Is it possible that it's been low since the last oil change and you just didn't notice? Perhaps it started a quart low and simply burned another half quart over the past 6000mi...
If you think you have an issue, start checking and logging your oil level on a regular basis. If you do have an issue, check your PCV. A stuck or leaky PCV can cause oil consumption. Also, a heavier oil can reduce the rate of oil burn. With the miles you run per week and the hot climate in San Antonio, I would consider a slightly thicker oil anyway - at least during the summer. Try a 0w40 syn if you're inclined, but don't expect the dealer to offer it for free.
Either way, good luck!