Can I place an unlocked iphone on the walmart unlimited plan?

So I'm going to buy a new iphone 4s off of ebay, because the prices are better. If I buy an unlocked iphone, will I be able to placer it on the walmart unlimited plan?

Added (1). Never have gotten a cell phone before, so i'm new to understanding what unlocked and stuff means.

It will work.

It will work, but unless it specifically is compatible with T-Mobile, it will only work for voice and texts. Data will be limited to 2G (EDGE). No MMS and Siri will only work on Wi-Fi