In my experience,NO. Sweet potatoes are not the same plant as white potatoes . White potatoes come from the nightshade group. They are more related to Tomatoes than the sweeet potatoe.
Sweet potatoes are Lpomoea Batatas from the convolvuloaea family.They are more closely related to the morning glory than the white poatatoe.
They are only distantly related to each other and have few common pests.
Your problem with potatoe bugs is normal. They will return each year unless you take very stingent steps.
I generaly do not grow them in the same garden from one year to the next. Not just because of potatoe bugs but cut worms and nematodes in the soil.
If you wish to grow some white potatoes plant some tomato plants amoung them. Not for a crop but the tomato plants have some repellent affect on the bugs. I do not know why. Another crop to put with them is nicotiana which is a pretty nocturnal flower related to the tobacco plant. The nicotine seems to repell them as well.
But your best results will be to cut the annual cycle of adult bugs and larvae in your potatoe field.
Sweet potatoes, BTW have more food value than white ones. The closer to purple the flesh the more flavanoids and anti Oxidents in the flesh.
Here is a good link about them
http://www.absoluteastronomy.com/topics/Sweet_potato
http://urbanext.illinois.edu/veggies/sweetpotato.cfm
One word of caution, sweet potatoes are tropical and will not endure any frost. Be careful at your lattitude.