X-Reality for mobile is presently missing from Xperia Z Ultra C6802 HSAP+ version and it is speculated that with the launch of Xperia Z Ultra LTE version, users will see X-Reality for Mobile in it.
X Reality for Mobile Xperia Z Ultra coming during 9 Sept., 2013 week
As seen from the White Paper published for Xperia Z Ultra LTE variants C6843/C6833/C6806, it seems X-Reality is missing from them also and it may come in the upcoming firmware updates for them.
Sony quoted it officially about the feature X-Reality for mobile in the white papers published for Xperia Z Ultra C6843/C6833/C6806/C6802 variants and will come in week commencing 9th September, 2013.
Check the below quote from white paper.
Yesterday we saw new 14.1.B.1.510, 14.1.B.1.515 Firmware Certified by PTCRB for all Xperia Z Ultra versions, well so X-Reality will come in those certified firmwares or with another higher firmware build certified 14.1.B.1.493.[ via – Sony Developers ]