Would it be better for Ph.D. graduate school admissions to compress my undergraduate years for a Master's Degree?
There is no rush.

Admissions won't give you bonus points for finishing early, so you're having to compete with people who took more time on the same amount of classes.

From my personal experience, I rushed and completed my undergrad a year early and my masters a semester early, but it didn't gain me much. In fact, my GPA took a beating.

Also, I wouldn't call it late if you're completing the masters in one additional semester, that would still be one semester early since it sounds like a 5 year program (4 + 1). 

If you want the best chances of getting into a top school: take your time. Either graduate with your bachelors or spend the two additional semesters getting your masters while attempting to get good letters, some research experience, and maybe even a publication. Trying to rush it further isn't going to help and gives you less time to do the important stuff for admissions (e.g., research and letters).