Don't think he's part of the family tree, but if I remember correctly from LEGO Island 2, the Infomaniac and Dr. Kilroy are colleagues, so... I guess that makes the Infomaniac an old family friend?
Err, Dr. Kilroy's voice in that game sounds nothing like that of the Infomniac aside from being your typical "old male professor" voice.
WE DO NOT SPEAK OF JAKE THUNDER.
Going by looks alone, Jake Raines definitely looks like a family member of Johnny Thunder. However, the reason I didn't include him here is because of two reasons. One being his nationality (while it's not impossible for our American friend to be related to everybody's favorite Aussie, it does make it a bit of a stretch). The other is that, unlike Josh Thunder, LEGO never confirmed a direct relationship and, unlike the upcoming Ultra Agents, probably never will (unless we get another tidbit of the sorts from a future edition of The LEGO Book, but that's speculation).
I was going to talk about that, but then I figured it would get too confusing. Hence I just went for simplest terms and wrote "uncle's brother" instead of "possibly uncle or father". Besides, no one wants to hear the possibility of Tim being the brother of Johnny Thunder himself!
On the old LEGO Club website, in an interview with Ogel back in late 2004 or early 2005 (it was around the end of Mission Deep Freeze), Ogel confirmed that Vladek is his great-great-great-great-great grandfather.
Of course, when you factor in the Evil Knight from the LEGO Minifigures series, who was employed by both Vladek and Cedric the Bull, the latter of whom interacted with the casts of LEGO Island and LEGO Soccer, both of which had a crossover with Alpha Team in a LEGO Magazine comic... well, the LEGO timeline implodes upon itself. Again.