As far as I know it only applies to gay couples but I'm not sure on that. Unfortunately your question overstates what he did. It's not a bill, its a "presidential memorandum" which won't have any effect on the law beyond the end of the Obama administration. Also the benefits are extremely limited, the only health care covered is for for long term illnesses. There's nothing for ordinary health care, survivors benefits etc. It's a crumb so he can say he did something on the issue. If heterosexual couples where eligible I doubt anyone would bother anyway.