I worked as an independant contractor in Texas for a company the reimbursed my expenses such as hotel, car rental, food, ect. The job was to travel the US and "secret" shop different companies. I was terminated. I know Texas state law allows 6 days for employees to be paid. Is this the same for independant contractors? Does this also apply to expense reimbursements?

In two words, No and No.

By way of explanation--Texas Payday Law specifically exempts independent contractors from coverage. This is the law that requires final WAGES to be paid by the 6th day after discharge, or by the next payday. This is for employees only. ICs may pursue contract enforcement through private actions.

Expenses for a contractor are normally figured in the contract price. At any rate, expenses are not part of what make up wages in Texas. There is no requirement for an employer to pay expenses for an employee. If you're a contractor, you don't come into the equation at all.