Optus is not great in synchronising all its systems. It appear in many cases any bonus data can take up to 2 months to appear across all platforms. I would recommend you contact LIVECHAT and have them confirm you are indeed listed as on a 35Gb plan (since each Gb over 2 potentially costs $10). If they agree you should be good to go.
You should generally be getting SMS warnings when you hit 50% usage, so if that hppens after 1Gb you'll also know theirs still an issue.