Well, no.

Semites are also e.g. Arabs. It comes from linguistic science and denotes people speaking Hebraic, Arabic or new-Aramaic languages. Look up the philologist August Ludwig von Schlözer who coined the term if that is new to you.

Also, criticizing a country is something very normal.

When one criticizes the Japan of 1930 to 1945 ... was this anti-zen? Or anti-nipponic? Or was it about their government?

When one criticizes the Syria of 1971-1924 ... what this anti-islamistic? Or anti-arabic? Or was it about their government, specifically their dictator?

When one criticizes the Israel of recent times ... is this anti-jewish? Or anti-semitic? Or is it about their government and various movements in said country?

It's only when we criticize the Israel government that suddenly people intermix politics with religion. And also with belonging to long extinct tribe groups. Or that they blame e.g. a synagogue congregation in Denmark with human-right violations of Israel settlers. Suddenly people stop being able to differentiate.

I see that there are countries that are anti-jewish (like Iran). And Persians aren't Semites, so maybe they are also anti-semitic, I can't judge this. But neither Iran nor Yemen or other puppet-organizations like the Hezbollah rule the UN. I'm quite sure that they can't even nudge the UN.

So claiming that the UN is anti-semitic is un-factional. I have seen zero evidence, and the people claiming this haven't brought up any evidence. The most they can bring up is that some UN sub-organization doesn't do the exact bidding of the current Israel government. Or that some UN sub-organization has the occasional mole or spy amongst them ... but hey, I don't want to know how many organizations have the odd moles or spy from the Mossad in them. That doesn't make them wholly israel-controlled.