The Vulcans in "Take Me Out to the Holosuite" were not racists. The Vulcan stated his physical superiority in a cold and logical manner, and what angered Sisko the most was the fact that he was right about it. The Vulcan was amused by Sisko's anger and competitiveness and studied him basically.
Solok displayed too much emotion to be considered a true Vulcan. Amusement and smugness are still emotions.
Besides: It is illogical to assert racial superiority. True, some Vulcans may be stronger than some humans, but the reverse is also surely true. There are weak Vulcans, and strong humans. An entire species can't be said to have the same level of physical strength.
I think it is entirely plausible to simply assume Solok is racist and dislikes humans. We've seen it before, of course. Not just in ENT, but also ST XI as well (the Vulcan Science Minister). Not all Vulcan characters in Trek have been so blatantly prejudiced, of course. Spock, T'Pol and Tuvok, for example, have all pointed out their differences with humans, but did not do so in such a flat-out bigoted fashion as Solok did.
And yes, the T'Kumbra
(Solok's ship) DID have a crew made up entirely of Vulcans. This was confirmed in dialogue in the episode, and of course, there was Solok's attitude. Would you expect Solok to WANT any human crewmembers to be serving under his command, after all? Or, conversely, would you (as a human) want to serve with somebody like him?