I'm considering the following scenario for employment and wondering how it will affect my taxes.

I am a resident of a large city, say Las Vegas, and am considering commuting to another distant city, say San Francisco, for 4 or 5 days a week for my main employment. This means that I have to pay for weekly airfare back and forth as well as a small apartment in SF. At the same time, I'm still paying a mortgage on a home in LV and my spouse is still working a full time job in LV, where I will return every weekend.

Normally, as I understand, this would mean that my tax home is in SF and my travel to/from and living expenses in SF would not be tax deductible. However, I'm also a musician on the side (my main employment is in tech), and I work as a part-time employee at a small establishment in LV by playing there for a few hours on the weekend. This employment adds up to around 10k-15k annually.

What I'm wondering is if this small employment in LV would have any effect on the tax deductible status of my travel expenses (and perhaps even some living expenses in LV).