Did a quick double check. No difference between Tectra V on/from a lvl 99 and 75. There doesn't seem to be anything % based or scaling about it.
The new values are:
Level 99 WHM/RDM
Protect: 163 -> 178 (15 DEF, previously 10)
Protect II: 163 -> 203 (40 DEF, previously 25)
Protect III: 163 -> 238 (70 DEF, previously 40)
Protect IV: 163 -> 283 (120 DEF, previously 55)
Protect V: 163 -> 338 (175 DEF, previously 60)
Protectra V (1 merit): 163 -> 338 (175 DEF, previously 60)
Protectra V (2 merits): 163 -> 343 (180 DEF, previously 62)
Protectra V (3 merits): 163 -> 348 (185 DEF, previously 64)
Protectra V (4 merits): 163 -> 353 (190 DEF, previously 66)
Protectra V (5 merits): 163 -> 358 (195 DEF, previously 68)
Augmented Relic +2 feet add +5 def per level for a max of 220.
I copied/edited Slycers post instead of mine because his looks better. Neither one of us has the earring or ring to see how much those add.