I checked the Ellis Island site in case there was an error in the transcription from the original manifest. Unfortunately, Brunadraga is on the original. The name does sound familiar, though I cannot place it at this time. It is most likely the German form for a Slovenian placename. However, of interest is the fact that Franc Potisek stated that he was going to his friend Lorenz Kaucic. On line 16 of the same manifest another person stated that they were going to their brother Lorenz Kaucic of Pittsburg. (the same individual and Pittsburg address) This person gave his place of origin as St. Martin. I could not locate the first name of this Kaucic. Rather than try to locate any further data on Franc Potisek (since the most important church records in the US are missing), I would suggest checking the church records for Smartno p. Litiji in the hope that he was born there.
With regards to the Matisko surname and its variations, I tried Matisko and Maticko on the Slovenian telephone directory. The other variations are not Slovenian. There are 6 Maticko in the directory, but no Matisko. I would suggest you try and leave messages for the Plahytka and Matisko (Matiszku, Matiscku, Matiszka) surnames on the Slovak and Czech Republic message boards. You may have better luck there.