This is what I found at the bcis web site:
Following-to-Join Benefits for Spouses
Please note: This section is only applicable to lawful permanent residents who did not gain their LPR status as an immediate relative (parent, spouse, or unmarried child under 21 years of age) of a U.S. citizen.
If you were married before you became a lawful permanent resident, and your spouse did not physically accompany you to the U.S., your spouse may be eligible for following-to-join benefits. This means that you do not have to submit a separate Form I-130, Petition for Alien Relative, for your spouse, and your spouse will not have to wait any extra time for a visa number to become available. In this case, you may simply notify a U.S. Consulate that you are a lawful permanent resident so that your spouse can apply for an immigrant visa. Your spouse may be eligible for following-to-join benefits if your relationship still exists and if one of the following is applicable:
You received a diversity immigrant visa
You received an employment-based immigrant visa
You received an immigrant visa based on your relationship to your U.S. citizen sibling
You received an immigrant visa based on your relationship to your U.S. citizen parent when you were already married
If you fall into one of these categories, please submit the following information to the Bureau of Citizenship and Immigration Services:
Form I-824, Application for Action on an Approved Application or Petition
A copy of the original application or petition that was used to apply for your immigrant status
A copy of the I-797, Notice of Action, for your original application or petition
A copy of your alien registration receipt card or I-551
If the I-824 is approved, BCIS will notify a U.S. consulate that you are a lawful permanent resident so that your spouse can apply for a following-to-join immigrant visa. Your spouse must then contact the local U.S. consulate to complete the processing.
You should file the I-824 at the BCIS office that took the most recent action on your case.
I TALKED TO MY LAWYER AND SHE DID NOT KNOW ABOUT THIS - WAS INSISTING ON THE FAMILY BASED PETITION i.e. is 5-6 YEARS WAIT.