Just because the UIA (whoever they are) have placed a couple of URLs in the same article does NOT prove they both have the same owner.
They are related by history, context and both have similar folks researching them. All well and good but so what? Doesn't prove what you're claiming.
Here's a direct quote from the site itself;
"After the death of Pastor Russell in 1916, J.F. Rutherford took control of the IBSA, acting in violation of Pastor Russell's Will and the Watchtower Bylaws. By 1931 J.F. Rutherford had radically changed and reorganized the Watchtower into a different organization. He named his new organization "Jehovah's Witnesses," in order to distinguish it from the various groups formed by the 75% of original Bible Students no longer connected. Hundreds of these Bible Student congregations worldwide have continued to the present, thus constituting a continuation of the original IBSA. These Bible Students remain united in the original early Watchtower beliefs taught by Pastor Russell."
Does that sound like a Watchtower controlled site to you?