At least you got drinks served while you sat!
Similar situation happened to me a few weeks back. Three different planes with an eight hour arrival delay. Plat line very helpful, GA's not.
Send TTU a note with mileage request, although a three hour delay isn't all that bad lately
.
You won't get segment creds but should get mileage bonus posted into your account - IF you ask for it.
(I asked for segment creds in my situation and was reminded of the policy "flown segments only).
When flying SEA-OGG last October, did a turn-around and emergency landing back in SEA and asked for segment cred for air time based on the policy of a take-off and landing. But as it was the same flight number - no luck.
Ah well, good luck - you never know what TTU will give you so ask for whatever you want!