Yes it is Bound
ALL Store items are either Bind to Character or Bind to Account
This is done so as to stop people paying for in-game gold
"How would they do that?" you might ask.
You spend real money on Turbine Points (TP)
You spend TP on a Store Item (example ... the 100% crit tome)
You put the Item on the AH for stupid amount of In-game Gold
HAF-X | ROG Crosshair V Formula Z | AMD FX 9370 4.4Ghz Black | 32Gb RAM | R9 290 4Gb (x2) | LG BD-RE | 500GB Samsung 850 EVO 550/540 SSD | Win10 Pro | WEI - 8.5