When can a new spouse be added to the EB-5 application?

You can get married and file the I-130 for her. However, the spouse of an LPR has a waiting period under the F2A visa category. Assuming you receive your I-829 approval when your wife's visa becomes current, she will be able to obtain LPR status, without first obtaining CR status as a dependent of an EB-5 investor. However, if your I-829 is denied, her LPR will be terminated as well.

If you are a green card holder, you may file for your spouse, but there is a waiting period for her immigrant visa to become available under the U.S. Department of State rules. Look at the visa bulletin published by Department of State on a monthly basis. Her category for a relative petition is F2A. There will be a wait time for her to either be able to start the consular process upon approval of your relative petition by USCIS (if she is abroad) or adjust status in the United States upon approval of your relative petition by USCIS (if she is in another lawful status in the United States, such as student visa, work visa, etc.).

It may be possible to add her through the I-829, but you are correct that after obtaining full lawful permanent residency you can petition for a foreign spouse.

You should have married before conditional card approval. Now she has to wait about two years; it's called the F2A category.

You may file for her, but there is no immediate visa available to her. There will be a waiting period determined under the visa rules of the Department of State.

You can get married and file an I-130 petition for her now as a conditional green card holder. But, the priority date is not current. It is complicated on how and when to file your wife's I-130 if she is in the United States. Please consult with an attorney before you file the I-130 for her.