Quite possible dumb question about Ennoia's Theater

As only the second multi-clan card (that I can think of) to be printed, Ennoia's Theater begs an interesting question:

Does it require a Methuselah to control vampires belonging to both BOTH Gangrel and Gangrel Anti-Tribu, or only one of the two?

According to the rules, 1.6.1.3 General, Card requirements:

Requirements for Playing Cards. . . . only a Methuselah who controls a ready minion who meets the requirements of a master card can play it.

This implies that it requires BOTH clans, as the requirement area of the card shows two clans.

However, Treaty of Laibach specifically mentions requiring both Tremere and Followers of Set, while having both icons in the sidebar, which implies that Treaty of Laibach is an exception to a standardized "either/or" ruling.

So I can see it both ways, but I'm leaning toward requiring either clan rather than both.

Which is the intended requirement of the card?

Either Gangrel or Gangrel Anti.

see also all of the !Tre/Tre cards e.g. Create Gargoyle/Soul of the Earth,.
It makes more implicit sense that you only need one of the clans with an action card [as a vampire can't be of two clans -at least not yet]