Some conservatives, including Gabriel Malor of the Federalist, have said that Congress just made a mistake in 1986 when it passed the Reagan immigration bill. They didn't
mean to leave out spouses and children, they just "had not considered and not included" them. So Reagan, and Bush after him, were just dealing with unintended consequences of a bill Congress had recently passed — making it different from Obama's actions today.
That's in line with how Sen. Chuck Schumer, a Democrat, characterized the law in 1987; the New York Times (as highlighted by Malor), paraphrasing Schumer, said that Congress kept the law "deliberately vague."
But when the Senate Judiciary Committee sent the Reagan bill to the full Senate, it wasn't vague at all — despite what Schumer claimed later.
It made it clear that it didn't intend to legalize the families of IRCA beneficiaries. Here's what the Judiciary Committee report said (as quoted, in full, in a court case from 1988, in which an IRCA applicant's spouse was denied relief):
It is the intent of the Committee that the families of legalized aliens will obtain no special petitioning right by virtue of the legalization. They will be required to "wait in line" in the same manner as immediate family members of other new resident aliens.
The executive actions that Reagan and Bush took didn't let anyone jump the line — they just allowed them to stay in the US until they could actually get in line for legal status. But
it's worth noting that the people Reagan and Bush protected had specifically been left out.