Short answer most likely not.
Unless your lines are really good which from the look of things they arent as you are only getting 54Mbps when using them so most likely you would only waste money on the 500mbit powerline adaptor as they still have to go over the same lines and tests have shown most people don't get much more speed out of them if any even on good lines.
If you really want to be able to max out your line get a cat 5e or 6 cable pulled which is what I did when I got upgraded to 120mbit and my 200mbit powerline adaptors only gave me about 70mbit.
If pulling a network cable isnt an option you might actually get better speed with good wireless equipment than the powerline option.
Imho for a little time and effort you can get a cable pulled and then if you need multiple devices plugged in get a small switch etc and you will be able to get the full speed your broadband gives you. I'm now enjoying maxing out my 120mbit connection from the pc upstairs
