A Wireless connection should have more than enough bandwidth to play video over it
Internet over Wireless
Consider the speed of your internet connection. If you're on broadband your internet speed could range anywhere from 0.5 Mbit/s to 8 Mbit/s or higher depending on your service provider. Think of the data you download from the internet as running water and your wireless connection is the pipe. As long as the water isn't running at a faster rate than your pipe can accommodate everything will be fine.
If you're connected wirelessly at 54 Mbit/s then you should never have any problems with internet or video playing over your wireless network because your wireless connection can accommodate much more data than is being used by simply going on the internet or playing a video.
Video over Wireless
The same principle applies here. For example, you may have a high quality video encoded at 2 Mbit/s. Again, the amount of data that needs to be streamed is less than the size of your wireless pipe. If you're connecting with 802.11g you could be browsing the internet and playing the video at the same time, stutter free.
Note: See the article on GSpot to see how you can figure out the bit rate of your videos.
If you remember this principle then it seems obvious that just because you're on a wireless connection it doesn't mean that the internet won't be as fast or videos can't be streamed. Just remember, your internet connection is like a straw feeding water into a wireless connection that is the size of a fire hose...for some reason that sounds dirty even though it wasn't supposed to.