Did you get upgraded? I've tried KVS tool and seen nothing available for the next umpteen months.
Indeed, C Award/Upgrade Availability on that route is extremely limited, but it does exist, e.g.:
[KVS Availability Tool 6.4.0/Diamond - SNT: Awards/StarAlliance/JP-ANA-SP1]
Code:
LAX Los Angeles Intl CA US [KLAX]
BKK Bangkok Intl TH [VTBS]
TUE 27 Mar 2012 | 1 Seat
Carrier Flight From Depart To Arrive A/C St Availability
--------- ------ ---- -------- ---- -------- --- -- -------------
TG 795 LAX 23:20 BKK 06:40 +2 345 0 FS/ CS+ YS+