As a temp fix when using G8 BT and clothing, I simply zero out the BT nipple sliders and use the DAZ nipple sliders. This makes the clothing follow the base figure shape.
Few, and I mean VERY few clothing items have a dense enough mesh to show more than a simple tent over the nipples, you won't notice the difference in the render.
Then when the figure is nude, I simply remove the DAZ nipples and add back the BT nipples. :)
You can also save a shape preset of just the BT graft so you have an easy 1-click way to restore your customized BT nipples, just remember to zero out the DAZ nipples first.
If you're using gargantuan huge nipples, that may be difficult to replicate with the DAZ sliders.
When I run into things like this I select the clothing item and then go to:
Edit/object/geometry/add smoothing modifier
Now that the clothing item has a smoothing modifier, go to the parameters tab, scroll down to Collision Item, Collision Iterations and Smoothing Iterations. Set the Collision Item to BT and try cranking up the Collision Iterations between 8 and 12, and the Smoothing Iterations to around 6. You can go higher, just be aware this can cause slower processors to hang and possibly crash to desktop.
This method can also be used to force clothing to follow G9 Breastacular in many cases.
If that doesn't work, either you've created nipple/breast shapes that no clothing has the mesh density to accommodate (way too big) or the clothing item is an older, very low density mesh. That's not a commentary on anyones nipple size preferences, just a limitation of the software :)
Hope this info helps!