Wants comma, not semi-colon.

CH: That's what I thought. Then I saw the Oracle wording for Whip Vine, Traproot Kami and Aether Membrane. I was somewhat shocked.

I could never remember either, but now I'm puzzled too. So it's just defender/reach that gets a semicolon? I agree they seem connected, but huh. I don't know if that's deliberate, or left over from an oracle update somehow?

I wonder if it might actually be because they've errataed in some reminder text. Every other combination of abilities seem to take a comma, so I might just declare I don't know what they're doing with those three, and make this fit the general rule rather than the specific rule.

Yep, after some Oracle trawling, I think the rule is: they try to put multiple reminder-texted keywords on one line, with parens explaining all of the keywords at once, as on Mirri, Cat Warrior or Skyhunter Prowler. But if they're errataing in reminder text for one keyword but not others, they separate them with semicolons, as on Icatian Skirmishers, Knights of Thorn, and Whip Vine and friends.

So since I've not got reminder text, I can just use a comma. Phew. The semicolon looked really weird.