Short answer: No, it is not double taxation.
Tax is based on income in this regard. The tax that the employees pay is the tax related to their personal income. The tax is related to the individual, not the company. The individual pays it, on the individual's behalf. It is the individual's income, not the company's.
Wages are deducted from revenue as part of establishing income, and are not taxed as part of the company's income. Wages represent the income of the individual, therefore the taxes collected on that income represent taxes collected related to the income of the INDIVIDUAL, not the COMPANY. Money that the company has left over after paying it's wages rent bills etc is the company's income, and that's what they're taxed on.
In order for it to be double taxation, the company would have to be taxed on the money BEFORE wages were paid, AND collect taxes on the wages themselves. But since the wages are deducted (among other things) from the amount being taxed from the company, they are not in fact being double-taxed.