And when was that? I recall an issue some time back, probably last year, where the furniture bonuses were borked up. It took RW awhile to figure out what was wrong and get them set straight again.
From may 2011 to july 2011. I am guessing you have been misinformed, much like back when house furniture came out and was put in guild caslte and lost its functionality, yet instead of refunding those dias/furniture the tooltip was changed to state the furniture would lose its functionality when placed in the castle.
Minimum level for furniture bonuses is level 25.
Higher the level, higher the bonus XP/TP.
I do not see a difference in the bonus gained between logging off as my druid, scout, or warden in terms of gain, but that may be due to not a significant lvl difference there.
I do know that there is a max amount of bonus that can be gained based on character lvl. Once that number is reached, no more bonus is gained.