To clarify your question, the 525 has de-ice boots on the horizontal tail leading edges, not the elevator leading edges....
The Citation 525 was flight tested with ice shapes on the vertical tail and found that ice does not have an aerodynamic or stability effect on the aircraft; it only increases drag slightly. Therefore the 525 (CJ), 525A (CJ2), and the new 525B (CJ3) being certified do not have ice protection on the vertical tail.
One reason that boots are used on the 525 HT and bleed air on the wings may be engine bleed air capacity limitations to also operate HT anti-ice.
The higher end jets tend to have bleed air & electric. The leading edges are smoother with bleed air compared to de-ice rubber boots. Also rubber boots have more maintenance than "shiney leading edges".
I believe the Model 500 & 550 (Bravo) have VT
de-ice boots. However non of the other Citations have VT
The new Citation 680 (Sovereign) and Citation X have bleed air on HT and wing.
The Citation 560XL has bleed air wing and boots on HT.
Citation 560 Ultra has electric wing inboard; boots wing outboard and HT.
Citation 560 Encore has electric/bleed air wing and boots on HT.
The 550 Bravo was discussed in a previous posting.
There is another ice protection technology not previously mentioned. The Citation 552 has TKS on the wing and HT. This is basically a fluid the comes out through tiny holes in the leading edge.
Boeing Flown: 701,702,703;717;720;721,722;731,732,733,734,735,737,738,739;741,742,743,744,747SP;752,753;762,763;772,773.