She realised later that power and authority are addictive, and you need boundaries, checks and balances. That still doesn't make what Egwene's oath of fealty similar to what Elaida's fourth oath. The contexts are completely different, and the degree is completely different. What Egwene did was machiavellian, but not tyranical.

What was "shocking" from Egwene is that she asked for an oath for something which the sisters by Law already owed the Amyrlin: obedience within the confines of her authority. It was insulting. She told them "I don't trust you, so if you want me to take the risk of protecting your secrets you will have to give me proof that I can trust you by an oath of fealty). Implicitely the Aes Sedai are trusted to obey the Amyrlin without that oath. And make no mistake - the sisters she asked an oath from didn't see this as tyranical, they were in part insulted that Egwene implied they could not be trusted, and pissed that she turned the tables on them and gained the authority that was hers in truth but they dreamed of wielding through her. She neutralized schemers and used them to bring into control other schemers who also refused to recognize her authority (the Hall), no more. Egwene's means were uncustomary, and not "nice", but her goal was to make the circle and Hall follow the system. Elaida, on the other hand, wanted to get rid of the system altogether.

Egwene was asking for no more than what any Lord or ruler ask. It's no different from Faile asking fealty from Morgase and co. to place them under her protection, except for Aes Sedai to Amyrlin that oath isn't customary. Siuan considered that Egwene was walking on dangerous political ground for breaking away from custom. But that wasn't an earth shattering move either. If it were, Lelaine would have used her discovery of the facts to raise hell and get the Hall to depose Egwene, or put her on trial. But in truth, revealing it would mostly have embarrassed the sisters who swore and gain Lelaine nothing, so instead she blackmailed the sisters to obey her in turn.

But otherwise, Egwene gave them secret orders that fell under her authority to issue, not unlawful orders. Egwene took the means to gain secretely the authority she was supposed to have but the Hall and circle, that considered her merely a figurehead, wasn't intending to give her. These women had influence and intended to wield political power through Egwene. She took back from them authority which was hers not theirs, by Law. The one request she made of them that fell out of customs (not even of law. I'm referring to her request that they reveal the identities of the AH) they flatly refused to obey, oath or no oath.

Elaida wanted (mused/dreamed about, anyway) was to take the obedience within the confines of the Law the sisters owe the Hall and Amyrlin and transform it into an oath of universal obedience to the Amyrlin bound by the Oath Rod. With that oath she transformed the position of Amyrlin Seat, already powerful but subject to checks and balances, into that of a pure tyrant unbound by Law. From a position similar to that of a monarch to a purely despotic position. She could ask anything of any sister and the OR would force them to obey. She could censure the Hall as she wished with that Oath. She could make herself totally untouchable. The whole tower would be enslaved to the will of a single woman, absolutely.

Elaida was reaching for tyrany. Egwene merely did what she did to gradually gain the authority she was supposed to have in the first place. There's no reason to call her an hypocrite. Not over this anyway.