I think the semantics are confusing, but I don't believe Cottle is suggesting that position is a fence or collar. It's an underlying long coupled with a bearish fence. He is suggesting that, synthetically, the long underlying plus short call is a bull spread because it's equivalent to long two atm calls plus short one otm call (ratio'd bull spread). Likewise, the long underlying is akin to short two atm puts and long one otm put (ratio'd bull spread).
To answer your question, no, a fence is not the same as a bull spread. A "fence" in typical parlance can be bearish if one is long a put, short a call, with no position in the underlying. It's only bullish if long call, short put, and no position in underlying.