In short....no.
Magnesium is an element and will be present in the "magnesium with B6" as a compound (could be the oxide, citrate, bisglycinate etc) with some vitamin B6 added. The magnesium citrate is just that (although both versions will have inert filler to make them into pills).
The important thing is this....if you need/want to take a magnesium supplement, look for the amount of available magnesium (in milligrams) on the label - it's the only way to compare different products and assess value for money.