Lots of people have problems streaming blu rays over wireless. DVDs will probably work. I wouldn't recommend it, unless the wireless router is close by. Some people are ok streaming up to 720p but have problems streaming 1080p. This is obviously dependent on the quality of the rip and other factors, like wireless interference. Powerline is better, but some people still have problems with things such as noisy appliances reducing the bitrate.
My advice is to get a large flash drive or external hard drive, and play it over usb instead of wireless or powerline. Or, get a WD live hub and copy movies to it before you watch.