In this neck of the woods that would make it a 2015 production year.
US VIN system similar but not the same as UK Australia and NZ usage. For starters the year character/digit is not the same sequence in line.
SMTTLC3735
J842289
Bingo 2018
How to Identify bike model from VIN Number in UK
The 10th to 17th positions are used as the 'vehicle identifier section' (VIS). This is used by the manufacturer to identify the individual vehicle in question.
USA/Canada 10th is year, UK/Europe 11th is year. This is Model year not actual production date. My 2010 model Roadster with an 'A' for 2010 was issued it's VIN in Dec 2009 (12/2009) as marked on my VIN plate.
I believe (12/2009) is most probably the date it enters Triumph factory inventory as a bike destined for a particular market NOT the date it was actually assembled.
BMW typically makes all the following years models from September the previous year.
For Triumph motorcycles 12th-17th is a sequential 6 digit number.
Your 11th character, the digit 6, is 2006 model year in UK / Europe
ISO Standard 3779 system used in Europe and many other parts of the world. Mine is A for 2010.
Date year code is the 10th character for USA / Canada
FMVSS 115, Part 565 system.
This character can be either a digit or an Alpha character
Code =
Year
A = 1980 L = 1990 Y = 2000 A = 2010 L = 2020 Y = 2030
B = 1981 M = 1991 1 = 2001 B = 2011 M = 2021 1 = 2031
C = 1982 N = 1992 2 = 2002 C = 2012 N = 2022 2 = 2032
D = 1983 P = 1993 3 = 2003 D = 2013 P = 2023 3 = 2033
E = 1984 R = 1994 4 = 2004 E = 2014 R = 2024 4 = 2034
F = 1985 S = 1995 5 = 2005 F = 2015 S = 2025 5 = 2035
G = 1986 T = 1996 6 = 2006 G = 2016 T = 2026 6 = 2036
H = 1987 V = 1997 7 = 2007 H = 2017 V = 2027 7 = 2037
J = 1988 W = 1998 8 = 2008
J = 2018 W = 2028 8 = 2038
K = 1989 X = 1999 9 = 2009 K = 2019 X = 2029 9 = 2039