Unlike Pollard, Ames was indicted for treason. He was a traitor who gave critical defense secrets to a U.S. enemy. Ames' actions resulted in the deaths of at least 11 U.S. agents.
By contrast, Pollard gave information to an ally, Israel. This information was being secretly embargoed from Israel despite a signed information-sharing agreement between Israel and the US.
Jonathan Pollard was never accused of, or indicted for treason. Neither was he ever indicted for harming the US. Pollard's only indictment was one count of passing classified information to an ally. The median sentence this charge carries is 2 to 4 years. Despite this, without benefit of trial and as the result of a government-violated plea agreement, Jonathan Pollard received the same sentence as Ames - life imprisonment.
In many ways Ames' treatment has been far more benign than Pollard's. For example, Pollard's conditions of incarceration have consistently been far more harsh. Moreover, unlike Ames who was only briefly held in solitary confinement during his intial debriefing, Jonathan Pollard spent 7 of his 14 years in solitary confinement. He was also unjustly held for a year in a mental asylum for the criminally insane. There, he was routinely deprived of his clothing and his eyeglasses in attempts to humilate and "break" him. Doctors attest that he was NOT a patient.
For further information, here are some of the articles dealing with the Ames Case. There are many other articles that reference the Ames case as well on this web site.