The question of how to educate children about religion is complicated, because it isn't just a question of the religious affiliation of the parents, but also their views on parenting ethics and religious ethics. A strongly religious parent who believes religion should not be proselytized at all may disagree with a mildly religious person who is totally okay with proselytism (note that I am just using these as examples and don't mean to imply you fall into any particular category here). Furthermore, the opinion of the person on what role parents should play in forming their children's beliefs in general is very relevant. Some people think parents have a duty to educate their children about what they consider correct morals, and in some cases, religious beliefs. Others fall more along the lines of believing that parents should merely "guide" their children but avoid telling them what to believe.
I mention this because when you have this conversation with your wife, you need to be sensitive to the fact that all of these factors will play a role in how she feels about educating your children about religion. Try to understand what her opinions are and why she holds them; her reasons may or may not be what you think. Be open to hearing her concerns out and taking them seriously, and in exchange, you should be able to expect your concerns to be taken seriously too.
It is important that you also identify specifically what your own beliefs on these questions are (i.e. your religious beliefs, your ethical beliefs, and your beliefs about your role as a parent), and why you have them, because you will need to be able to tell your wife what you consider important and why.
It might go without saying, but you should approach this issue as a dialogue, not a demand or request. You and your wife are a team who must figure out how to best raise your children together, and approaching it this way is less likely to put her on the defensive and make her feel like you don't value her perspectives and beliefs (again, not just her religious beliefs, but her ethical and parental ideals).
I think it is a great idea to tell her why you think a basic knowledge of the theological landscape would be valuable to your children. In my own experience, people who are wary of aligning their children to a specific religion are often more okay with providing a broader education about different beliefs.
Perhaps a good way to summarize my advice is to consider asking yourself if your roles were reversed in some way (perhaps your wife wanted to distance the children from religion more than they are now), how would you want to be approached about this? How would you want your concerns and beliefs to be taken into account on her end?