Well to know the answer lets look at some dates. It is already well known that the Dragon Ball series as a whole was created long before Sonic was....still it took some time before the story ended up in Dragon Ball Z. So, Sonic the Hedgehog was originally released (looking at Japanese dates since these are originally Japanese created and it would be released there first) June 23, 1991. However, Super Sonic first appeared in Sonic the Hedgehog 2 which was released November 21, 1992. Now, hopefully most people realize that there was a Dragon Ball manga before the anime which was originally released November 10, 1985. Goku, first turned into a Super Saiyan in Dragon Ball Z volume 11 which was released August 7, 1991. Surprisingly, there's only a year's difference.
Honestly, it could have just been coincidental; however, it isn't a secret that Dragon Ball Z influenced a lot of other creative works because it was highly popular.
Now, here's a bit of trivia: The manga was created before the anime. As already mentioned Volume 11 of DBZ was released August 7, 1991. The anime Dragon Ball began airing in 1986 with DBZ beginning on April 26, 1989. Goku transformed into a Super Saiyan episode 95 of DBZ which aired June 19, 1991.