If you select some styled text in a text box or in a shape, these options come up, so these instructions do apply to iOS Numbers, for text boxes and shapes containing text. They do not, however, work for text in a cell.
In fact, if you copy styled text from a text box and paste it into a cell, the styling will be stripped. Some text styling is stripped on importing from the desktop version to the iOS version as well. So, apparently, the iOS version has much more limited support for text styling features in tables compared to the desktop version.
If you copy the whole cell with the styling you want, and paste it into the cell to which you want to apply that styling, it will bring its styling with it. You can then overwrite the content of the cell with new content which will still have the desired styling. This is obviously less than optimal if you have already entered the information into that cell.
If you have a number of cell ranges in your table (which may already contain data) that you want to have all styled the same, but you don't want to apply the styling to each range individually, one possible work-around would be:
- Add enough blank columns (or rows) to the table to accommodate all those ranges (i.e., double its size)
- Select and drag each range into the blank area
- Select a range including all the moved cells and apply the styling once, to all of them
- Move each range back to its original place
- Delete the extra columns
