Oban met a new neighbour puppy this morning and she is even worse than he is.  Only 12 weeks old and she is a very, very dominant, aggressive personality.  She did not put up with any guff from him and gave back as good as she got.  Oban is nearly twice her weight and height but she seemed to not notice that and attempted many times to mount him and be top dog.  This time it was her owners stepping in to cool things down, not me.  Her owners are experienced dog people and say she is aggressive with them too, which Oban is not.  Oban is sweet with people.  These neighbours are worried about how their puppy will be with their grandchildren.  We are going to try to get the two puppies out together for walks but now I am wondering if this new pup will teach Oban bad things.  Oban already has a tendancy to want to be the dominant dog with all other dogs he meets.  If this puppy welcomes his rough and tumble play will that encourage him to act that way more?  Any thoughts?

If this puppy welcomes his rough and tumble play will that encourage him to act that way more?  Any thoughts?

I wouldn't think so, infact it is more likely to have the opposite effect. Many bitches are extremely bossy and play aggressively, it has no bearing on how the adult bitch will be at all so tell your neighbours not to worry in that respect, but with regards to grandchildren they need to be on guard, pups teeth and nails are extremely sharp and she is likely to grab and tug at them, just advise them to put the pup in time out once she gets too excited and to keep vigilant. Her behaviour will calm down with consistancy, time outs and the advice on the bite stops here doc, which may be usefull for you to print off for them. 

People can have many dogs, all will have different personalities and a more aggressive and hyper pup can sometimes make people worry they have a pup with behavioural problems, but it is not so, they generally grow up to be lovely calm dogs. Just some can be absolute terrors when young.

Many bitches are extremely bossy and play aggressively,

My girly SBT is exactly like that apart from the aggression, she plays not in an aggressive way but deffo plays the most boisterous with the rest of the dogs and lets them know whos boss! lol

Well, I guess I will phone the lady and arrange at least one outing together.  I have seen many posts here stating that puppies learn good behaviour from well mannered older dogs so I figured the reverse could be true.  And I know our kittens who learned to play roughly with the dog played roughly with us too. 

I think it will be fine as long as she isn't his sole canine behaviour example.  This is why socialisation with positive things is so important, it puts and negative experiences in context when the good are the norm.

True.  If my dog had only played with the pup down the road he would be as out of control and wild as she is.  I don't mind him playing with her as they have a really good time but if she was his only playmate I dread to think what he would be like now