Q: is it obstruction of justice for a peace officer to keep info from another peace officer at a scene?

A: No, it doesn’t sound like obstruction of justice took place: it sounds more like a decision had to be made to protect both parties. In Texas, an arrest is mandatory in a domestic abuse report. Unfortunately for you, you’re spouse made the call and you did not. Prior incidents are irrelevant as to who is the aggressor in the current situation.

A: It isn't obstruction, but you should tell your criminal defense attorney about the discussion between the officers before they arrested you. These days, most officers wear body-mounted cameras and/or wireless microphones. If the first responders disagreed when their investigation occurred immediately after then incident then how could a jury be unanimously convinced, beyond a reasonable doubt, by second-hand information presented months or even years later by a prosecutor that wasn't even there?!? However, your attorney must act quickly to request copies of those recordings before they are destroyed.

It is true that what happened previously is irrelevant with regard to who was the first aggressor on this occasion. However, the Rules of Evidence explicitly ALLOW a defense based on Self Defense to bring up past incidents that illustrate the alleged victim's character for violence. Since it is a Family Violence case you can go into a bunch of stuff that would be excluded from evidence in a stranger-vs-stranger assault. (Article 38.371 Code of Criminal Procedure)

The requirement of Self Defense are fairly technical, and there are special rules for Family Violence, so it is important that you hire a local attorney with experience handling Family Violence cases involving self defense.