Learn both. I started in PHP as a hobby in high school, and then had various languages taught in college (Java, VB 6, VB.NET, C, C++). I then went on countless interviews and during the process of the interview (that would be my first job), it quickly hit me, they were a .NET shop and I thought all along they were a PHP shop (I screwed up, and confused two companies). Needless to say, it didn't matter in the end. I could think logically, I could solve problems, and I could answer their questions with the confidence they expected.
I was hired, and spent weeks learning C# (their own internal process required you to go through this training), and I successfully have been utilizing the .NET framework for the past 7 years. I still do PHP work on the side as well.
Needless to say, the question isn't which language is better, the question you should ask yourself, is am I competent at my job? Can I think logically, can I perform my duties, ask the right questions, etc. Language is purely syntax, it won't help you figure out how to solve a problem, it is just a mechanism you use to solve the problem.