If you are both residents of Massachusetts, you technically cannot get divorced in a foreign country because that would bypass the divorce laws of Massachusetts. But if your wife was still considered a resident of the DR, or a big maybe, if the DR still has legal jurisdiction over your Wife (or you), then it would be legal in Mass. Some Countries have a law that will consider you a resident for the purposes of granting of a divorce after staying there for a week (in order to get around this issue).
Hence, the strength of the divorce certificate and the terms of the divorce (alimony) depend on if you can prove the DR had jurisdiction over you or your ex, just one is enough.
Hence, you should be fine unless your ex takes you to court to challenge the validity of the divorce or the terms of the agreement. If you can prove the DR had jurisdiction, you'd be all set. And the answer to that depends upon the law in the DR.
There have been rare cases when the wife went to file for social security or something, they denied it saying the marriage was not legal due to the divorce not being valid under the laws of your State, often due to the place not having legal jurisdiction.
I had gotten divorce overseas as well. I have had zero issue or questioning using the foreign decree in getting remarried or getting a visa and greencard, etc.. with my new Wife. But we got divorced, same as you, in the country where she got married, but in my case she stayed in her Country, so no one can challenge the residency and hence the jurisdiction. Since your Wife is from DR and you got married there, probably you won't either, unless your Wife tries to challenge it. Then it would depend on how good your lawyers are and the judge.