Hello ESB_1,
It sounds as though you’ve run out of available storage on your iPhone, and noticed bookmarks no longer showing after running out of storage. Apple Support Communities is a great place for help! Although you didn’t sync Safari with iCloud, the bookmarks should be saved locally to the iPhone. Did you have the opportunity to walk through steps to clear storage on your iPhone? If not, try the recommendations in the following article to help increase the available storage.
How to check the storage on your iPhone, iPad, and iPod touch
After managing the storage you may want to restart the iPhone, then test to see if the bookmarks return.
Restart your iPhone
If the bookmarks don’t return then we would be looking at restoring to a backup if available. You can find the steps for restoring to a backup in the article below.
Restore your iPhone, iPad, or iPod touch from a backup
Have a great weekend!