thanks Ian - vastly better picture - I think this might be a case of the blind leading the blind

Photographing clear glass is often difficult but don't think you'll better this new one.
It's an intriguing piece, design wise, and from what I can see would be inclined to agree the inclusions aren't bubbles - possibly sand?? - I know that Wedgwood (Stennett-Willson - in the U.K.) did some clear cylindrical vases which were made using finely grained sand which gave an appearance similar to your piece. However, your suggestion of powdered glass may well be nearer the mark.
Aventurine/avventurina (not adventurine) refers to the decorative effect using metallic inclusions probably copper/gold/or silver, in the form of small flakes in very random distribution - very ancient method of decoration - mostly I think we tend to see copper coloured types here, although even iron filings have been used, apparently. I get the impression that most pieces decorated in this way (aventurine) do come from the Gulf of Venice (Murano).
How the inner walled effect has been produced I've no idea, although obviously some form of intricate blowing technique is high on the list, and it may well qualify as summerso - we now need someone who actually knows what they're talking about, but think probably not bollicine, but a very interesting piece.
P.S. in view of the apparently non-metallic inclusions here, I wonder if we should consider including Scandi. in the search area ?? - also bearing in mind the piece is basically clear glass.