Hi Michael, yes these kinds of organic bubbly type shapes are usually better dealt with in a polygon mesh based modeler which is focused on organic shape creation. These kinds of things are difficult to create with CAD toolsets.

You could try using ZSurf - that's a program that takes a bitmap in and uses the grayscale level of a pixel as a height value, so it makes a kind of heightfield surface over the bitmap and you set up gradients and shading on the bitmap to shape the surface. Check out here for a thread on that: http://moi3d.com/forum/index.php?webtag=MOI&msg=3825.2

There's also a program called ArtCAM which is heavily focused on building these kinds of 2.5D relief type shapes.

There's also a category of displacement brush stroke based sculpting programs like ZBrush, Scluptris, and 3D-Coat which are good tools for making raised organic patterns.

- Michael