Do any of the new O group company packs come with bases? If not, what's the recommended basing for O group at 1:1?

From the PDF rules

1.3 BASING
There Are No Fixed Base Sizes. Actual base sizes have no bearing on game mechanics
and it is irrelevant how any of the figures or models are based, as long as the individual
unit types, for example HQs, Company Commanders, rifle Sections, SMG Sections or antitank
Sections are recognisable and ideally that the opposing armies are based similarly. If
opposing armies are based significantly differently, then simply make allowances where
necessary.
1.4 SCALES
 ‘O’ Group is designed for use with 20mm, 15mm, 12mm/10mm or 6mm figures.
 Figure Scale: One infantry base = one section of approximately 10 men. One model
AFV or Gun represents two or three tanks or guns. One model transport represents two
standard size half-tracks or trucks or three smaller vehicles.

Nigel

The company packs do not come with bases.   We do provide them in the boxed starter set,  These are all 30x30, which can house a strip of four infantry, a single support weapon, most artillery pieces and most vehicles.