Does 5's get 30% TM from his zeta or just 15%?

Since other abilities like Vader's, JKR's and EP's abilities double-dip for allies with multiple relevant tags, I would be very surprised if 5's zeta doesn't.

... But no, I didn't test and verify it.

No, only 15%. When the effect is doubled (JKR lead, Vader unique) the wording says 'for each ally' of a certain faction, and they are tied with 'and'.
'Or' means when either of the conditions are fulfilled, doesn't double up when both are met.

Kool. Thanks guys.